Flat Tow Wrangler YJ (Informational - Long)
02-07-2007, 12:43 PM
#41
Guest
Posts: n/a
Re: Flat Tow Wrangler YJ (Informational - Long)
OK, so with my '84 CJ, AMC 20, Dana 300, and NV4500, I should put the t-case
in neutral and put the tranny in a gear. Do I need to disconnect the rear
drive shaft? Or, what is the downside of putting locking hubs on the rear?
"L.W. (Bill) ------ III" <----------@***.net> wrote in message
news:52scpuF1o2nm0U1@mid.individual.net...
> That's true with the Dana 20 and 300 with only one lever. I would
> appreciate it is someone with New Process transfer would confirm this, by
> simple putting theirs in neutral and jack up a front wheel, if they don't
> free wheeling hubs and see if you can turn the front driveshaft. I don't
> believe it's true, because this would quickly destroy one of the
> differentials.
> God Bless America, Bill 0|||||||0
> mailto:-------------------- http://www.----------.com/
>
> <edh3007@bellsouth.net> wrote in message
> news:1170785062.593064.102050@v33g2000cwv.googlegr oups.com...
>> I have a 1991 Jeep Wrangler YJ with the 2.5L four-cylinder and stock
>> five speed manual transmission. I assume it has the standard NP-231
>> transfer case.
>>
>> Although I have successfully flat-towed my YJ (maximum of about 400
>> miles one-way and then return about a week later), I've recently
>> learned that the NP-231 (at least of this era) does not have a "true"
>> neutral position. Instead, while it does uncouple the transmission
>> from the transfer case, it also couples the front and rear outputs
>> together. If the front axle is engaged this causes gear backlash with
>> the potential to destroy the transfer case. If the Center Axle
>> Disconnect (CAD) on the front axle is disconnected (disengaged?), then
>> the backlash is eliminated.
>>
>> The problem is that the vacuum operated CAD stays in the last position
>> it was put in. If you are preparing your YJ for flat towing and you
>> start the engine, the moment you shift the transfer case from 2WD to
>> Neutral the vacuum CAD engages the front axle. There you are with the
>> outputs of the transfer case locked together and the front axle live
>> instead of free-wheeling. Leaving you with the potential of blowing up
>> the transfer case.
>>
>> The standard way to disengage the CAD under normal conditions (i.e.
>> you've been in 4WD and are now ready to resume normal 2WD operation)
>> is to place the transfer case into 2WD and then put the transmission
>> into reverse and back up several feet. This puts the front axle back
>> into free-wheeling mode (assuming everything is working properly), and
>> you can put the transmission into normal gear and drive off.
>>
>> If you know the CAD is in this state then you can prepare for towing
>> simply by putting the transfer case into neutral without starting the
>> engine (no vacuum). Go ahead and put the transmission into neutral,
>> hook up to your tow vehicle and go. Some people recommend that you
>> leave the transmission in gear while towing. Since you have
>> disconnected the transmission when you put the transfer case in
>> neutral, this should not be necessary. Further, if the transmission is
>> in gear and the transfer case is accidently engaged (by a severe bump
>> maybe?) there will be bad consequences. You don't have to worry about
>> the transfer case lubrication because the rear output (which is
>> engaged) also drives the internal oil pump. As long as the CAD is
>> disengaged you are ready to tow.
>>
>> Apparently when I've towed my YJ I been fortunate in that a)I
>> typically back in to park, therefore I've left the jeep with the CAD
>> disengaged and b)I normally don't have any reason to start the jeep
>> prior to putting the transfer case into neutral before hooking it up
>> to be towed. Since I didn't understand what I was doing, I could very
>> easily have destroyed my transfer case without knowing why.
>>
>> Although I am comfortable with this, knowing how things work, there
>> are alternatives I discovered as I researched this issue.
>>
>> 1)Assuming that the CAD is already disengaged, you can just disconnect
>> the vacuum line from the CAD box. You'd be fine to start your engine
>> and move the jeep to the towing vehicle, hook up, put the transfer
>> case and transmission in neutral and go.
>>
>> 2)Install and use a Posi-Lock device instead of the vacuum CAD. Since
>> you control the front axle lock by cable, you should know the state it
>> is in.
>>
>> 3)Install and use external locking hubs. Not pleasant to use in foul
>> weather, but again you always know the state of the front axle because
>> you set it.
>>
>> 4)Install a transfer case conversion that gives you a true neutral.
>> You'd never have to worry about the state of the front axle when you
>> put the transfer case into neutral then.
>>
>> 5)Finally, of course, you can always tow your jeep on a trailer.
>>
>> Comments and questions are welcome.
>>
>> Your mileage may vary.
>> Vehicles in mirror are closer than they appear.
>> Cheers, Ed Humphries
>> Atlanta, Georgia
>>
>
>
in neutral and put the tranny in a gear. Do I need to disconnect the rear
drive shaft? Or, what is the downside of putting locking hubs on the rear?
"L.W. (Bill) ------ III" <----------@***.net> wrote in message
news:52scpuF1o2nm0U1@mid.individual.net...
> That's true with the Dana 20 and 300 with only one lever. I would
> appreciate it is someone with New Process transfer would confirm this, by
> simple putting theirs in neutral and jack up a front wheel, if they don't
> free wheeling hubs and see if you can turn the front driveshaft. I don't
> believe it's true, because this would quickly destroy one of the
> differentials.
> God Bless America, Bill 0|||||||0
> mailto:-------------------- http://www.----------.com/
>
> <edh3007@bellsouth.net> wrote in message
> news:1170785062.593064.102050@v33g2000cwv.googlegr oups.com...
>> I have a 1991 Jeep Wrangler YJ with the 2.5L four-cylinder and stock
>> five speed manual transmission. I assume it has the standard NP-231
>> transfer case.
>>
>> Although I have successfully flat-towed my YJ (maximum of about 400
>> miles one-way and then return about a week later), I've recently
>> learned that the NP-231 (at least of this era) does not have a "true"
>> neutral position. Instead, while it does uncouple the transmission
>> from the transfer case, it also couples the front and rear outputs
>> together. If the front axle is engaged this causes gear backlash with
>> the potential to destroy the transfer case. If the Center Axle
>> Disconnect (CAD) on the front axle is disconnected (disengaged?), then
>> the backlash is eliminated.
>>
>> The problem is that the vacuum operated CAD stays in the last position
>> it was put in. If you are preparing your YJ for flat towing and you
>> start the engine, the moment you shift the transfer case from 2WD to
>> Neutral the vacuum CAD engages the front axle. There you are with the
>> outputs of the transfer case locked together and the front axle live
>> instead of free-wheeling. Leaving you with the potential of blowing up
>> the transfer case.
>>
>> The standard way to disengage the CAD under normal conditions (i.e.
>> you've been in 4WD and are now ready to resume normal 2WD operation)
>> is to place the transfer case into 2WD and then put the transmission
>> into reverse and back up several feet. This puts the front axle back
>> into free-wheeling mode (assuming everything is working properly), and
>> you can put the transmission into normal gear and drive off.
>>
>> If you know the CAD is in this state then you can prepare for towing
>> simply by putting the transfer case into neutral without starting the
>> engine (no vacuum). Go ahead and put the transmission into neutral,
>> hook up to your tow vehicle and go. Some people recommend that you
>> leave the transmission in gear while towing. Since you have
>> disconnected the transmission when you put the transfer case in
>> neutral, this should not be necessary. Further, if the transmission is
>> in gear and the transfer case is accidently engaged (by a severe bump
>> maybe?) there will be bad consequences. You don't have to worry about
>> the transfer case lubrication because the rear output (which is
>> engaged) also drives the internal oil pump. As long as the CAD is
>> disengaged you are ready to tow.
>>
>> Apparently when I've towed my YJ I been fortunate in that a)I
>> typically back in to park, therefore I've left the jeep with the CAD
>> disengaged and b)I normally don't have any reason to start the jeep
>> prior to putting the transfer case into neutral before hooking it up
>> to be towed. Since I didn't understand what I was doing, I could very
>> easily have destroyed my transfer case without knowing why.
>>
>> Although I am comfortable with this, knowing how things work, there
>> are alternatives I discovered as I researched this issue.
>>
>> 1)Assuming that the CAD is already disengaged, you can just disconnect
>> the vacuum line from the CAD box. You'd be fine to start your engine
>> and move the jeep to the towing vehicle, hook up, put the transfer
>> case and transmission in neutral and go.
>>
>> 2)Install and use a Posi-Lock device instead of the vacuum CAD. Since
>> you control the front axle lock by cable, you should know the state it
>> is in.
>>
>> 3)Install and use external locking hubs. Not pleasant to use in foul
>> weather, but again you always know the state of the front axle because
>> you set it.
>>
>> 4)Install a transfer case conversion that gives you a true neutral.
>> You'd never have to worry about the state of the front axle when you
>> put the transfer case into neutral then.
>>
>> 5)Finally, of course, you can always tow your jeep on a trailer.
>>
>> Comments and questions are welcome.
>>
>> Your mileage may vary.
>> Vehicles in mirror are closer than they appear.
>> Cheers, Ed Humphries
>> Atlanta, Georgia
>>
>
>
02-07-2007, 01:22 PM
#42
Guest
Posts: n/a
Re: Flat Tow Wrangler YJ (Informational - Long)
I am not sure that the Dana 300 will oil itself properly if driven from the
rear in neutral. You need to get an owner's manual and see what it says.
An NV4500 upgrade doesn't really change anything in that respect. For your
vehicle disconnecting the rear drive shaft sounds like a good idea. Locking
hubs require you to install a free floating axle, which is a good thing, but
there is the expense.
Earle
"Peter Stolz" <peachyracer@yahoo.com> wrote in message
news:Lcoyh.3542$4H1.2820@newssvr17.news.prodigy.ne t...
> OK, so with my '84 CJ, AMC 20, Dana 300, and NV4500, I should put the
t-case
> in neutral and put the tranny in a gear. Do I need to disconnect the rear
> drive shaft? Or, what is the downside of putting locking hubs on the
rear?
>
>
> "L.W. (Bill) ------ III" <----------@***.net> wrote in message
> news:52scpuF1o2nm0U1@mid.individual.net...
> > That's true with the Dana 20 and 300 with only one lever. I would
> > appreciate it is someone with New Process transfer would confirm this,
by
> > simple putting theirs in neutral and jack up a front wheel, if they
don't
> > free wheeling hubs and see if you can turn the front driveshaft. I don't
> > believe it's true, because this would quickly destroy one of the
> > differentials.
> > God Bless America, Bill 0|||||||0
> > mailto:-------------------- http://www.----------.com/
> >
> > <edh3007@bellsouth.net> wrote in message
> > news:1170785062.593064.102050@v33g2000cwv.googlegr oups.com...
> >> I have a 1991 Jeep Wrangler YJ with the 2.5L four-cylinder and stock
> >> five speed manual transmission. I assume it has the standard NP-231
> >> transfer case.
> >>
> >> Although I have successfully flat-towed my YJ (maximum of about 400
> >> miles one-way and then return about a week later), I've recently
> >> learned that the NP-231 (at least of this era) does not have a "true"
> >> neutral position. Instead, while it does uncouple the transmission
> >> from the transfer case, it also couples the front and rear outputs
> >> together. If the front axle is engaged this causes gear backlash with
> >> the potential to destroy the transfer case. If the Center Axle
> >> Disconnect (CAD) on the front axle is disconnected (disengaged?), then
> >> the backlash is eliminated.
> >>
> >> The problem is that the vacuum operated CAD stays in the last position
> >> it was put in. If you are preparing your YJ for flat towing and you
> >> start the engine, the moment you shift the transfer case from 2WD to
> >> Neutral the vacuum CAD engages the front axle. There you are with the
> >> outputs of the transfer case locked together and the front axle live
> >> instead of free-wheeling. Leaving you with the potential of blowing up
> >> the transfer case.
> >>
> >> The standard way to disengage the CAD under normal conditions (i.e.
> >> you've been in 4WD and are now ready to resume normal 2WD operation)
> >> is to place the transfer case into 2WD and then put the transmission
> >> into reverse and back up several feet. This puts the front axle back
> >> into free-wheeling mode (assuming everything is working properly), and
> >> you can put the transmission into normal gear and drive off.
> >>
> >> If you know the CAD is in this state then you can prepare for towing
> >> simply by putting the transfer case into neutral without starting the
> >> engine (no vacuum). Go ahead and put the transmission into neutral,
> >> hook up to your tow vehicle and go. Some people recommend that you
> >> leave the transmission in gear while towing. Since you have
> >> disconnected the transmission when you put the transfer case in
> >> neutral, this should not be necessary. Further, if the transmission is
> >> in gear and the transfer case is accidently engaged (by a severe bump
> >> maybe?) there will be bad consequences. You don't have to worry about
> >> the transfer case lubrication because the rear output (which is
> >> engaged) also drives the internal oil pump. As long as the CAD is
> >> disengaged you are ready to tow.
> >>
> >> Apparently when I've towed my YJ I been fortunate in that a)I
> >> typically back in to park, therefore I've left the jeep with the CAD
> >> disengaged and b)I normally don't have any reason to start the jeep
> >> prior to putting the transfer case into neutral before hooking it up
> >> to be towed. Since I didn't understand what I was doing, I could very
> >> easily have destroyed my transfer case without knowing why.
> >>
> >> Although I am comfortable with this, knowing how things work, there
> >> are alternatives I discovered as I researched this issue.
> >>
> >> 1)Assuming that the CAD is already disengaged, you can just disconnect
> >> the vacuum line from the CAD box. You'd be fine to start your engine
> >> and move the jeep to the towing vehicle, hook up, put the transfer
> >> case and transmission in neutral and go.
> >>
> >> 2)Install and use a Posi-Lock device instead of the vacuum CAD. Since
> >> you control the front axle lock by cable, you should know the state it
> >> is in.
> >>
> >> 3)Install and use external locking hubs. Not pleasant to use in foul
> >> weather, but again you always know the state of the front axle because
> >> you set it.
> >>
> >> 4)Install a transfer case conversion that gives you a true neutral.
> >> You'd never have to worry about the state of the front axle when you
> >> put the transfer case into neutral then.
> >>
> >> 5)Finally, of course, you can always tow your jeep on a trailer.
> >>
> >> Comments and questions are welcome.
> >>
> >> Your mileage may vary.
> >> Vehicles in mirror are closer than they appear.
> >> Cheers, Ed Humphries
> >> Atlanta, Georgia
> >>
> >
> >
>
>
rear in neutral. You need to get an owner's manual and see what it says.
An NV4500 upgrade doesn't really change anything in that respect. For your
vehicle disconnecting the rear drive shaft sounds like a good idea. Locking
hubs require you to install a free floating axle, which is a good thing, but
there is the expense.
Earle
"Peter Stolz" <peachyracer@yahoo.com> wrote in message
news:Lcoyh.3542$4H1.2820@newssvr17.news.prodigy.ne t...
> OK, so with my '84 CJ, AMC 20, Dana 300, and NV4500, I should put the
t-case
> in neutral and put the tranny in a gear. Do I need to disconnect the rear
> drive shaft? Or, what is the downside of putting locking hubs on the
rear?
>
>
> "L.W. (Bill) ------ III" <----------@***.net> wrote in message
> news:52scpuF1o2nm0U1@mid.individual.net...
> > That's true with the Dana 20 and 300 with only one lever. I would
> > appreciate it is someone with New Process transfer would confirm this,
by
> > simple putting theirs in neutral and jack up a front wheel, if they
don't
> > free wheeling hubs and see if you can turn the front driveshaft. I don't
> > believe it's true, because this would quickly destroy one of the
> > differentials.
> > God Bless America, Bill 0|||||||0
> > mailto:-------------------- http://www.----------.com/
> >
> > <edh3007@bellsouth.net> wrote in message
> > news:1170785062.593064.102050@v33g2000cwv.googlegr oups.com...
> >> I have a 1991 Jeep Wrangler YJ with the 2.5L four-cylinder and stock
> >> five speed manual transmission. I assume it has the standard NP-231
> >> transfer case.
> >>
> >> Although I have successfully flat-towed my YJ (maximum of about 400
> >> miles one-way and then return about a week later), I've recently
> >> learned that the NP-231 (at least of this era) does not have a "true"
> >> neutral position. Instead, while it does uncouple the transmission
> >> from the transfer case, it also couples the front and rear outputs
> >> together. If the front axle is engaged this causes gear backlash with
> >> the potential to destroy the transfer case. If the Center Axle
> >> Disconnect (CAD) on the front axle is disconnected (disengaged?), then
> >> the backlash is eliminated.
> >>
> >> The problem is that the vacuum operated CAD stays in the last position
> >> it was put in. If you are preparing your YJ for flat towing and you
> >> start the engine, the moment you shift the transfer case from 2WD to
> >> Neutral the vacuum CAD engages the front axle. There you are with the
> >> outputs of the transfer case locked together and the front axle live
> >> instead of free-wheeling. Leaving you with the potential of blowing up
> >> the transfer case.
> >>
> >> The standard way to disengage the CAD under normal conditions (i.e.
> >> you've been in 4WD and are now ready to resume normal 2WD operation)
> >> is to place the transfer case into 2WD and then put the transmission
> >> into reverse and back up several feet. This puts the front axle back
> >> into free-wheeling mode (assuming everything is working properly), and
> >> you can put the transmission into normal gear and drive off.
> >>
> >> If you know the CAD is in this state then you can prepare for towing
> >> simply by putting the transfer case into neutral without starting the
> >> engine (no vacuum). Go ahead and put the transmission into neutral,
> >> hook up to your tow vehicle and go. Some people recommend that you
> >> leave the transmission in gear while towing. Since you have
> >> disconnected the transmission when you put the transfer case in
> >> neutral, this should not be necessary. Further, if the transmission is
> >> in gear and the transfer case is accidently engaged (by a severe bump
> >> maybe?) there will be bad consequences. You don't have to worry about
> >> the transfer case lubrication because the rear output (which is
> >> engaged) also drives the internal oil pump. As long as the CAD is
> >> disengaged you are ready to tow.
> >>
> >> Apparently when I've towed my YJ I been fortunate in that a)I
> >> typically back in to park, therefore I've left the jeep with the CAD
> >> disengaged and b)I normally don't have any reason to start the jeep
> >> prior to putting the transfer case into neutral before hooking it up
> >> to be towed. Since I didn't understand what I was doing, I could very
> >> easily have destroyed my transfer case without knowing why.
> >>
> >> Although I am comfortable with this, knowing how things work, there
> >> are alternatives I discovered as I researched this issue.
> >>
> >> 1)Assuming that the CAD is already disengaged, you can just disconnect
> >> the vacuum line from the CAD box. You'd be fine to start your engine
> >> and move the jeep to the towing vehicle, hook up, put the transfer
> >> case and transmission in neutral and go.
> >>
> >> 2)Install and use a Posi-Lock device instead of the vacuum CAD. Since
> >> you control the front axle lock by cable, you should know the state it
> >> is in.
> >>
> >> 3)Install and use external locking hubs. Not pleasant to use in foul
> >> weather, but again you always know the state of the front axle because
> >> you set it.
> >>
> >> 4)Install a transfer case conversion that gives you a true neutral.
> >> You'd never have to worry about the state of the front axle when you
> >> put the transfer case into neutral then.
> >>
> >> 5)Finally, of course, you can always tow your jeep on a trailer.
> >>
> >> Comments and questions are welcome.
> >>
> >> Your mileage may vary.
> >> Vehicles in mirror are closer than they appear.
> >> Cheers, Ed Humphries
> >> Atlanta, Georgia
> >>
> >
> >
>
>
02-07-2007, 01:22 PM
#43
Guest
Posts: n/a
Re: Flat Tow Wrangler YJ (Informational - Long)
I am not sure that the Dana 300 will oil itself properly if driven from the
rear in neutral. You need to get an owner's manual and see what it says.
An NV4500 upgrade doesn't really change anything in that respect. For your
vehicle disconnecting the rear drive shaft sounds like a good idea. Locking
hubs require you to install a free floating axle, which is a good thing, but
there is the expense.
Earle
"Peter Stolz" <peachyracer@yahoo.com> wrote in message
news:Lcoyh.3542$4H1.2820@newssvr17.news.prodigy.ne t...
> OK, so with my '84 CJ, AMC 20, Dana 300, and NV4500, I should put the
t-case
> in neutral and put the tranny in a gear. Do I need to disconnect the rear
> drive shaft? Or, what is the downside of putting locking hubs on the
rear?
>
>
> "L.W. (Bill) ------ III" <----------@***.net> wrote in message
> news:52scpuF1o2nm0U1@mid.individual.net...
> > That's true with the Dana 20 and 300 with only one lever. I would
> > appreciate it is someone with New Process transfer would confirm this,
by
> > simple putting theirs in neutral and jack up a front wheel, if they
don't
> > free wheeling hubs and see if you can turn the front driveshaft. I don't
> > believe it's true, because this would quickly destroy one of the
> > differentials.
> > God Bless America, Bill 0|||||||0
> > mailto:-------------------- http://www.----------.com/
> >
> > <edh3007@bellsouth.net> wrote in message
> > news:1170785062.593064.102050@v33g2000cwv.googlegr oups.com...
> >> I have a 1991 Jeep Wrangler YJ with the 2.5L four-cylinder and stock
> >> five speed manual transmission. I assume it has the standard NP-231
> >> transfer case.
> >>
> >> Although I have successfully flat-towed my YJ (maximum of about 400
> >> miles one-way and then return about a week later), I've recently
> >> learned that the NP-231 (at least of this era) does not have a "true"
> >> neutral position. Instead, while it does uncouple the transmission
> >> from the transfer case, it also couples the front and rear outputs
> >> together. If the front axle is engaged this causes gear backlash with
> >> the potential to destroy the transfer case. If the Center Axle
> >> Disconnect (CAD) on the front axle is disconnected (disengaged?), then
> >> the backlash is eliminated.
> >>
> >> The problem is that the vacuum operated CAD stays in the last position
> >> it was put in. If you are preparing your YJ for flat towing and you
> >> start the engine, the moment you shift the transfer case from 2WD to
> >> Neutral the vacuum CAD engages the front axle. There you are with the
> >> outputs of the transfer case locked together and the front axle live
> >> instead of free-wheeling. Leaving you with the potential of blowing up
> >> the transfer case.
> >>
> >> The standard way to disengage the CAD under normal conditions (i.e.
> >> you've been in 4WD and are now ready to resume normal 2WD operation)
> >> is to place the transfer case into 2WD and then put the transmission
> >> into reverse and back up several feet. This puts the front axle back
> >> into free-wheeling mode (assuming everything is working properly), and
> >> you can put the transmission into normal gear and drive off.
> >>
> >> If you know the CAD is in this state then you can prepare for towing
> >> simply by putting the transfer case into neutral without starting the
> >> engine (no vacuum). Go ahead and put the transmission into neutral,
> >> hook up to your tow vehicle and go. Some people recommend that you
> >> leave the transmission in gear while towing. Since you have
> >> disconnected the transmission when you put the transfer case in
> >> neutral, this should not be necessary. Further, if the transmission is
> >> in gear and the transfer case is accidently engaged (by a severe bump
> >> maybe?) there will be bad consequences. You don't have to worry about
> >> the transfer case lubrication because the rear output (which is
> >> engaged) also drives the internal oil pump. As long as the CAD is
> >> disengaged you are ready to tow.
> >>
> >> Apparently when I've towed my YJ I been fortunate in that a)I
> >> typically back in to park, therefore I've left the jeep with the CAD
> >> disengaged and b)I normally don't have any reason to start the jeep
> >> prior to putting the transfer case into neutral before hooking it up
> >> to be towed. Since I didn't understand what I was doing, I could very
> >> easily have destroyed my transfer case without knowing why.
> >>
> >> Although I am comfortable with this, knowing how things work, there
> >> are alternatives I discovered as I researched this issue.
> >>
> >> 1)Assuming that the CAD is already disengaged, you can just disconnect
> >> the vacuum line from the CAD box. You'd be fine to start your engine
> >> and move the jeep to the towing vehicle, hook up, put the transfer
> >> case and transmission in neutral and go.
> >>
> >> 2)Install and use a Posi-Lock device instead of the vacuum CAD. Since
> >> you control the front axle lock by cable, you should know the state it
> >> is in.
> >>
> >> 3)Install and use external locking hubs. Not pleasant to use in foul
> >> weather, but again you always know the state of the front axle because
> >> you set it.
> >>
> >> 4)Install a transfer case conversion that gives you a true neutral.
> >> You'd never have to worry about the state of the front axle when you
> >> put the transfer case into neutral then.
> >>
> >> 5)Finally, of course, you can always tow your jeep on a trailer.
> >>
> >> Comments and questions are welcome.
> >>
> >> Your mileage may vary.
> >> Vehicles in mirror are closer than they appear.
> >> Cheers, Ed Humphries
> >> Atlanta, Georgia
> >>
> >
> >
>
>
rear in neutral. You need to get an owner's manual and see what it says.
An NV4500 upgrade doesn't really change anything in that respect. For your
vehicle disconnecting the rear drive shaft sounds like a good idea. Locking
hubs require you to install a free floating axle, which is a good thing, but
there is the expense.
Earle
"Peter Stolz" <peachyracer@yahoo.com> wrote in message
news:Lcoyh.3542$4H1.2820@newssvr17.news.prodigy.ne t...
> OK, so with my '84 CJ, AMC 20, Dana 300, and NV4500, I should put the
t-case
> in neutral and put the tranny in a gear. Do I need to disconnect the rear
> drive shaft? Or, what is the downside of putting locking hubs on the
rear?
>
>
> "L.W. (Bill) ------ III" <----------@***.net> wrote in message
> news:52scpuF1o2nm0U1@mid.individual.net...
> > That's true with the Dana 20 and 300 with only one lever. I would
> > appreciate it is someone with New Process transfer would confirm this,
by
> > simple putting theirs in neutral and jack up a front wheel, if they
don't
> > free wheeling hubs and see if you can turn the front driveshaft. I don't
> > believe it's true, because this would quickly destroy one of the
> > differentials.
> > God Bless America, Bill 0|||||||0
> > mailto:-------------------- http://www.----------.com/
> >
> > <edh3007@bellsouth.net> wrote in message
> > news:1170785062.593064.102050@v33g2000cwv.googlegr oups.com...
> >> I have a 1991 Jeep Wrangler YJ with the 2.5L four-cylinder and stock
> >> five speed manual transmission. I assume it has the standard NP-231
> >> transfer case.
> >>
> >> Although I have successfully flat-towed my YJ (maximum of about 400
> >> miles one-way and then return about a week later), I've recently
> >> learned that the NP-231 (at least of this era) does not have a "true"
> >> neutral position. Instead, while it does uncouple the transmission
> >> from the transfer case, it also couples the front and rear outputs
> >> together. If the front axle is engaged this causes gear backlash with
> >> the potential to destroy the transfer case. If the Center Axle
> >> Disconnect (CAD) on the front axle is disconnected (disengaged?), then
> >> the backlash is eliminated.
> >>
> >> The problem is that the vacuum operated CAD stays in the last position
> >> it was put in. If you are preparing your YJ for flat towing and you
> >> start the engine, the moment you shift the transfer case from 2WD to
> >> Neutral the vacuum CAD engages the front axle. There you are with the
> >> outputs of the transfer case locked together and the front axle live
> >> instead of free-wheeling. Leaving you with the potential of blowing up
> >> the transfer case.
> >>
> >> The standard way to disengage the CAD under normal conditions (i.e.
> >> you've been in 4WD and are now ready to resume normal 2WD operation)
> >> is to place the transfer case into 2WD and then put the transmission
> >> into reverse and back up several feet. This puts the front axle back
> >> into free-wheeling mode (assuming everything is working properly), and
> >> you can put the transmission into normal gear and drive off.
> >>
> >> If you know the CAD is in this state then you can prepare for towing
> >> simply by putting the transfer case into neutral without starting the
> >> engine (no vacuum). Go ahead and put the transmission into neutral,
> >> hook up to your tow vehicle and go. Some people recommend that you
> >> leave the transmission in gear while towing. Since you have
> >> disconnected the transmission when you put the transfer case in
> >> neutral, this should not be necessary. Further, if the transmission is
> >> in gear and the transfer case is accidently engaged (by a severe bump
> >> maybe?) there will be bad consequences. You don't have to worry about
> >> the transfer case lubrication because the rear output (which is
> >> engaged) also drives the internal oil pump. As long as the CAD is
> >> disengaged you are ready to tow.
> >>
> >> Apparently when I've towed my YJ I been fortunate in that a)I
> >> typically back in to park, therefore I've left the jeep with the CAD
> >> disengaged and b)I normally don't have any reason to start the jeep
> >> prior to putting the transfer case into neutral before hooking it up
> >> to be towed. Since I didn't understand what I was doing, I could very
> >> easily have destroyed my transfer case without knowing why.
> >>
> >> Although I am comfortable with this, knowing how things work, there
> >> are alternatives I discovered as I researched this issue.
> >>
> >> 1)Assuming that the CAD is already disengaged, you can just disconnect
> >> the vacuum line from the CAD box. You'd be fine to start your engine
> >> and move the jeep to the towing vehicle, hook up, put the transfer
> >> case and transmission in neutral and go.
> >>
> >> 2)Install and use a Posi-Lock device instead of the vacuum CAD. Since
> >> you control the front axle lock by cable, you should know the state it
> >> is in.
> >>
> >> 3)Install and use external locking hubs. Not pleasant to use in foul
> >> weather, but again you always know the state of the front axle because
> >> you set it.
> >>
> >> 4)Install a transfer case conversion that gives you a true neutral.
> >> You'd never have to worry about the state of the front axle when you
> >> put the transfer case into neutral then.
> >>
> >> 5)Finally, of course, you can always tow your jeep on a trailer.
> >>
> >> Comments and questions are welcome.
> >>
> >> Your mileage may vary.
> >> Vehicles in mirror are closer than they appear.
> >> Cheers, Ed Humphries
> >> Atlanta, Georgia
> >>
> >
> >
>
>
02-07-2007, 01:22 PM
#44
Guest
Posts: n/a
Re: Flat Tow Wrangler YJ (Informational - Long)
I am not sure that the Dana 300 will oil itself properly if driven from the
rear in neutral. You need to get an owner's manual and see what it says.
An NV4500 upgrade doesn't really change anything in that respect. For your
vehicle disconnecting the rear drive shaft sounds like a good idea. Locking
hubs require you to install a free floating axle, which is a good thing, but
there is the expense.
Earle
"Peter Stolz" <peachyracer@yahoo.com> wrote in message
news:Lcoyh.3542$4H1.2820@newssvr17.news.prodigy.ne t...
> OK, so with my '84 CJ, AMC 20, Dana 300, and NV4500, I should put the
t-case
> in neutral and put the tranny in a gear. Do I need to disconnect the rear
> drive shaft? Or, what is the downside of putting locking hubs on the
rear?
>
>
> "L.W. (Bill) ------ III" <----------@***.net> wrote in message
> news:52scpuF1o2nm0U1@mid.individual.net...
> > That's true with the Dana 20 and 300 with only one lever. I would
> > appreciate it is someone with New Process transfer would confirm this,
by
> > simple putting theirs in neutral and jack up a front wheel, if they
don't
> > free wheeling hubs and see if you can turn the front driveshaft. I don't
> > believe it's true, because this would quickly destroy one of the
> > differentials.
> > God Bless America, Bill 0|||||||0
> > mailto:-------------------- http://www.----------.com/
> >
> > <edh3007@bellsouth.net> wrote in message
> > news:1170785062.593064.102050@v33g2000cwv.googlegr oups.com...
> >> I have a 1991 Jeep Wrangler YJ with the 2.5L four-cylinder and stock
> >> five speed manual transmission. I assume it has the standard NP-231
> >> transfer case.
> >>
> >> Although I have successfully flat-towed my YJ (maximum of about 400
> >> miles one-way and then return about a week later), I've recently
> >> learned that the NP-231 (at least of this era) does not have a "true"
> >> neutral position. Instead, while it does uncouple the transmission
> >> from the transfer case, it also couples the front and rear outputs
> >> together. If the front axle is engaged this causes gear backlash with
> >> the potential to destroy the transfer case. If the Center Axle
> >> Disconnect (CAD) on the front axle is disconnected (disengaged?), then
> >> the backlash is eliminated.
> >>
> >> The problem is that the vacuum operated CAD stays in the last position
> >> it was put in. If you are preparing your YJ for flat towing and you
> >> start the engine, the moment you shift the transfer case from 2WD to
> >> Neutral the vacuum CAD engages the front axle. There you are with the
> >> outputs of the transfer case locked together and the front axle live
> >> instead of free-wheeling. Leaving you with the potential of blowing up
> >> the transfer case.
> >>
> >> The standard way to disengage the CAD under normal conditions (i.e.
> >> you've been in 4WD and are now ready to resume normal 2WD operation)
> >> is to place the transfer case into 2WD and then put the transmission
> >> into reverse and back up several feet. This puts the front axle back
> >> into free-wheeling mode (assuming everything is working properly), and
> >> you can put the transmission into normal gear and drive off.
> >>
> >> If you know the CAD is in this state then you can prepare for towing
> >> simply by putting the transfer case into neutral without starting the
> >> engine (no vacuum). Go ahead and put the transmission into neutral,
> >> hook up to your tow vehicle and go. Some people recommend that you
> >> leave the transmission in gear while towing. Since you have
> >> disconnected the transmission when you put the transfer case in
> >> neutral, this should not be necessary. Further, if the transmission is
> >> in gear and the transfer case is accidently engaged (by a severe bump
> >> maybe?) there will be bad consequences. You don't have to worry about
> >> the transfer case lubrication because the rear output (which is
> >> engaged) also drives the internal oil pump. As long as the CAD is
> >> disengaged you are ready to tow.
> >>
> >> Apparently when I've towed my YJ I been fortunate in that a)I
> >> typically back in to park, therefore I've left the jeep with the CAD
> >> disengaged and b)I normally don't have any reason to start the jeep
> >> prior to putting the transfer case into neutral before hooking it up
> >> to be towed. Since I didn't understand what I was doing, I could very
> >> easily have destroyed my transfer case without knowing why.
> >>
> >> Although I am comfortable with this, knowing how things work, there
> >> are alternatives I discovered as I researched this issue.
> >>
> >> 1)Assuming that the CAD is already disengaged, you can just disconnect
> >> the vacuum line from the CAD box. You'd be fine to start your engine
> >> and move the jeep to the towing vehicle, hook up, put the transfer
> >> case and transmission in neutral and go.
> >>
> >> 2)Install and use a Posi-Lock device instead of the vacuum CAD. Since
> >> you control the front axle lock by cable, you should know the state it
> >> is in.
> >>
> >> 3)Install and use external locking hubs. Not pleasant to use in foul
> >> weather, but again you always know the state of the front axle because
> >> you set it.
> >>
> >> 4)Install a transfer case conversion that gives you a true neutral.
> >> You'd never have to worry about the state of the front axle when you
> >> put the transfer case into neutral then.
> >>
> >> 5)Finally, of course, you can always tow your jeep on a trailer.
> >>
> >> Comments and questions are welcome.
> >>
> >> Your mileage may vary.
> >> Vehicles in mirror are closer than they appear.
> >> Cheers, Ed Humphries
> >> Atlanta, Georgia
> >>
> >
> >
>
>
rear in neutral. You need to get an owner's manual and see what it says.
An NV4500 upgrade doesn't really change anything in that respect. For your
vehicle disconnecting the rear drive shaft sounds like a good idea. Locking
hubs require you to install a free floating axle, which is a good thing, but
there is the expense.
Earle
"Peter Stolz" <peachyracer@yahoo.com> wrote in message
news:Lcoyh.3542$4H1.2820@newssvr17.news.prodigy.ne t...
> OK, so with my '84 CJ, AMC 20, Dana 300, and NV4500, I should put the
t-case
> in neutral and put the tranny in a gear. Do I need to disconnect the rear
> drive shaft? Or, what is the downside of putting locking hubs on the
rear?
>
>
> "L.W. (Bill) ------ III" <----------@***.net> wrote in message
> news:52scpuF1o2nm0U1@mid.individual.net...
> > That's true with the Dana 20 and 300 with only one lever. I would
> > appreciate it is someone with New Process transfer would confirm this,
by
> > simple putting theirs in neutral and jack up a front wheel, if they
don't
> > free wheeling hubs and see if you can turn the front driveshaft. I don't
> > believe it's true, because this would quickly destroy one of the
> > differentials.
> > God Bless America, Bill 0|||||||0
> > mailto:-------------------- http://www.----------.com/
> >
> > <edh3007@bellsouth.net> wrote in message
> > news:1170785062.593064.102050@v33g2000cwv.googlegr oups.com...
> >> I have a 1991 Jeep Wrangler YJ with the 2.5L four-cylinder and stock
> >> five speed manual transmission. I assume it has the standard NP-231
> >> transfer case.
> >>
> >> Although I have successfully flat-towed my YJ (maximum of about 400
> >> miles one-way and then return about a week later), I've recently
> >> learned that the NP-231 (at least of this era) does not have a "true"
> >> neutral position. Instead, while it does uncouple the transmission
> >> from the transfer case, it also couples the front and rear outputs
> >> together. If the front axle is engaged this causes gear backlash with
> >> the potential to destroy the transfer case. If the Center Axle
> >> Disconnect (CAD) on the front axle is disconnected (disengaged?), then
> >> the backlash is eliminated.
> >>
> >> The problem is that the vacuum operated CAD stays in the last position
> >> it was put in. If you are preparing your YJ for flat towing and you
> >> start the engine, the moment you shift the transfer case from 2WD to
> >> Neutral the vacuum CAD engages the front axle. There you are with the
> >> outputs of the transfer case locked together and the front axle live
> >> instead of free-wheeling. Leaving you with the potential of blowing up
> >> the transfer case.
> >>
> >> The standard way to disengage the CAD under normal conditions (i.e.
> >> you've been in 4WD and are now ready to resume normal 2WD operation)
> >> is to place the transfer case into 2WD and then put the transmission
> >> into reverse and back up several feet. This puts the front axle back
> >> into free-wheeling mode (assuming everything is working properly), and
> >> you can put the transmission into normal gear and drive off.
> >>
> >> If you know the CAD is in this state then you can prepare for towing
> >> simply by putting the transfer case into neutral without starting the
> >> engine (no vacuum). Go ahead and put the transmission into neutral,
> >> hook up to your tow vehicle and go. Some people recommend that you
> >> leave the transmission in gear while towing. Since you have
> >> disconnected the transmission when you put the transfer case in
> >> neutral, this should not be necessary. Further, if the transmission is
> >> in gear and the transfer case is accidently engaged (by a severe bump
> >> maybe?) there will be bad consequences. You don't have to worry about
> >> the transfer case lubrication because the rear output (which is
> >> engaged) also drives the internal oil pump. As long as the CAD is
> >> disengaged you are ready to tow.
> >>
> >> Apparently when I've towed my YJ I been fortunate in that a)I
> >> typically back in to park, therefore I've left the jeep with the CAD
> >> disengaged and b)I normally don't have any reason to start the jeep
> >> prior to putting the transfer case into neutral before hooking it up
> >> to be towed. Since I didn't understand what I was doing, I could very
> >> easily have destroyed my transfer case without knowing why.
> >>
> >> Although I am comfortable with this, knowing how things work, there
> >> are alternatives I discovered as I researched this issue.
> >>
> >> 1)Assuming that the CAD is already disengaged, you can just disconnect
> >> the vacuum line from the CAD box. You'd be fine to start your engine
> >> and move the jeep to the towing vehicle, hook up, put the transfer
> >> case and transmission in neutral and go.
> >>
> >> 2)Install and use a Posi-Lock device instead of the vacuum CAD. Since
> >> you control the front axle lock by cable, you should know the state it
> >> is in.
> >>
> >> 3)Install and use external locking hubs. Not pleasant to use in foul
> >> weather, but again you always know the state of the front axle because
> >> you set it.
> >>
> >> 4)Install a transfer case conversion that gives you a true neutral.
> >> You'd never have to worry about the state of the front axle when you
> >> put the transfer case into neutral then.
> >>
> >> 5)Finally, of course, you can always tow your jeep on a trailer.
> >>
> >> Comments and questions are welcome.
> >>
> >> Your mileage may vary.
> >> Vehicles in mirror are closer than they appear.
> >> Cheers, Ed Humphries
> >> Atlanta, Georgia
> >>
> >
> >
>
>
02-07-2007, 01:22 PM
#45
Guest
Posts: n/a
Re: Flat Tow Wrangler YJ (Informational - Long)
I am not sure that the Dana 300 will oil itself properly if driven from the
rear in neutral. You need to get an owner's manual and see what it says.
An NV4500 upgrade doesn't really change anything in that respect. For your
vehicle disconnecting the rear drive shaft sounds like a good idea. Locking
hubs require you to install a free floating axle, which is a good thing, but
there is the expense.
Earle
"Peter Stolz" <peachyracer@yahoo.com> wrote in message
news:Lcoyh.3542$4H1.2820@newssvr17.news.prodigy.ne t...
> OK, so with my '84 CJ, AMC 20, Dana 300, and NV4500, I should put the
t-case
> in neutral and put the tranny in a gear. Do I need to disconnect the rear
> drive shaft? Or, what is the downside of putting locking hubs on the
rear?
>
>
> "L.W. (Bill) ------ III" <----------@***.net> wrote in message
> news:52scpuF1o2nm0U1@mid.individual.net...
> > That's true with the Dana 20 and 300 with only one lever. I would
> > appreciate it is someone with New Process transfer would confirm this,
by
> > simple putting theirs in neutral and jack up a front wheel, if they
don't
> > free wheeling hubs and see if you can turn the front driveshaft. I don't
> > believe it's true, because this would quickly destroy one of the
> > differentials.
> > God Bless America, Bill 0|||||||0
> > mailto:-------------------- http://www.----------.com/
> >
> > <edh3007@bellsouth.net> wrote in message
> > news:1170785062.593064.102050@v33g2000cwv.googlegr oups.com...
> >> I have a 1991 Jeep Wrangler YJ with the 2.5L four-cylinder and stock
> >> five speed manual transmission. I assume it has the standard NP-231
> >> transfer case.
> >>
> >> Although I have successfully flat-towed my YJ (maximum of about 400
> >> miles one-way and then return about a week later), I've recently
> >> learned that the NP-231 (at least of this era) does not have a "true"
> >> neutral position. Instead, while it does uncouple the transmission
> >> from the transfer case, it also couples the front and rear outputs
> >> together. If the front axle is engaged this causes gear backlash with
> >> the potential to destroy the transfer case. If the Center Axle
> >> Disconnect (CAD) on the front axle is disconnected (disengaged?), then
> >> the backlash is eliminated.
> >>
> >> The problem is that the vacuum operated CAD stays in the last position
> >> it was put in. If you are preparing your YJ for flat towing and you
> >> start the engine, the moment you shift the transfer case from 2WD to
> >> Neutral the vacuum CAD engages the front axle. There you are with the
> >> outputs of the transfer case locked together and the front axle live
> >> instead of free-wheeling. Leaving you with the potential of blowing up
> >> the transfer case.
> >>
> >> The standard way to disengage the CAD under normal conditions (i.e.
> >> you've been in 4WD and are now ready to resume normal 2WD operation)
> >> is to place the transfer case into 2WD and then put the transmission
> >> into reverse and back up several feet. This puts the front axle back
> >> into free-wheeling mode (assuming everything is working properly), and
> >> you can put the transmission into normal gear and drive off.
> >>
> >> If you know the CAD is in this state then you can prepare for towing
> >> simply by putting the transfer case into neutral without starting the
> >> engine (no vacuum). Go ahead and put the transmission into neutral,
> >> hook up to your tow vehicle and go. Some people recommend that you
> >> leave the transmission in gear while towing. Since you have
> >> disconnected the transmission when you put the transfer case in
> >> neutral, this should not be necessary. Further, if the transmission is
> >> in gear and the transfer case is accidently engaged (by a severe bump
> >> maybe?) there will be bad consequences. You don't have to worry about
> >> the transfer case lubrication because the rear output (which is
> >> engaged) also drives the internal oil pump. As long as the CAD is
> >> disengaged you are ready to tow.
> >>
> >> Apparently when I've towed my YJ I been fortunate in that a)I
> >> typically back in to park, therefore I've left the jeep with the CAD
> >> disengaged and b)I normally don't have any reason to start the jeep
> >> prior to putting the transfer case into neutral before hooking it up
> >> to be towed. Since I didn't understand what I was doing, I could very
> >> easily have destroyed my transfer case without knowing why.
> >>
> >> Although I am comfortable with this, knowing how things work, there
> >> are alternatives I discovered as I researched this issue.
> >>
> >> 1)Assuming that the CAD is already disengaged, you can just disconnect
> >> the vacuum line from the CAD box. You'd be fine to start your engine
> >> and move the jeep to the towing vehicle, hook up, put the transfer
> >> case and transmission in neutral and go.
> >>
> >> 2)Install and use a Posi-Lock device instead of the vacuum CAD. Since
> >> you control the front axle lock by cable, you should know the state it
> >> is in.
> >>
> >> 3)Install and use external locking hubs. Not pleasant to use in foul
> >> weather, but again you always know the state of the front axle because
> >> you set it.
> >>
> >> 4)Install a transfer case conversion that gives you a true neutral.
> >> You'd never have to worry about the state of the front axle when you
> >> put the transfer case into neutral then.
> >>
> >> 5)Finally, of course, you can always tow your jeep on a trailer.
> >>
> >> Comments and questions are welcome.
> >>
> >> Your mileage may vary.
> >> Vehicles in mirror are closer than they appear.
> >> Cheers, Ed Humphries
> >> Atlanta, Georgia
> >>
> >
> >
>
>
rear in neutral. You need to get an owner's manual and see what it says.
An NV4500 upgrade doesn't really change anything in that respect. For your
vehicle disconnecting the rear drive shaft sounds like a good idea. Locking
hubs require you to install a free floating axle, which is a good thing, but
there is the expense.
Earle
"Peter Stolz" <peachyracer@yahoo.com> wrote in message
news:Lcoyh.3542$4H1.2820@newssvr17.news.prodigy.ne t...
> OK, so with my '84 CJ, AMC 20, Dana 300, and NV4500, I should put the
t-case
> in neutral and put the tranny in a gear. Do I need to disconnect the rear
> drive shaft? Or, what is the downside of putting locking hubs on the
rear?
>
>
> "L.W. (Bill) ------ III" <----------@***.net> wrote in message
> news:52scpuF1o2nm0U1@mid.individual.net...
> > That's true with the Dana 20 and 300 with only one lever. I would
> > appreciate it is someone with New Process transfer would confirm this,
by
> > simple putting theirs in neutral and jack up a front wheel, if they
don't
> > free wheeling hubs and see if you can turn the front driveshaft. I don't
> > believe it's true, because this would quickly destroy one of the
> > differentials.
> > God Bless America, Bill 0|||||||0
> > mailto:-------------------- http://www.----------.com/
> >
> > <edh3007@bellsouth.net> wrote in message
> > news:1170785062.593064.102050@v33g2000cwv.googlegr oups.com...
> >> I have a 1991 Jeep Wrangler YJ with the 2.5L four-cylinder and stock
> >> five speed manual transmission. I assume it has the standard NP-231
> >> transfer case.
> >>
> >> Although I have successfully flat-towed my YJ (maximum of about 400
> >> miles one-way and then return about a week later), I've recently
> >> learned that the NP-231 (at least of this era) does not have a "true"
> >> neutral position. Instead, while it does uncouple the transmission
> >> from the transfer case, it also couples the front and rear outputs
> >> together. If the front axle is engaged this causes gear backlash with
> >> the potential to destroy the transfer case. If the Center Axle
> >> Disconnect (CAD) on the front axle is disconnected (disengaged?), then
> >> the backlash is eliminated.
> >>
> >> The problem is that the vacuum operated CAD stays in the last position
> >> it was put in. If you are preparing your YJ for flat towing and you
> >> start the engine, the moment you shift the transfer case from 2WD to
> >> Neutral the vacuum CAD engages the front axle. There you are with the
> >> outputs of the transfer case locked together and the front axle live
> >> instead of free-wheeling. Leaving you with the potential of blowing up
> >> the transfer case.
> >>
> >> The standard way to disengage the CAD under normal conditions (i.e.
> >> you've been in 4WD and are now ready to resume normal 2WD operation)
> >> is to place the transfer case into 2WD and then put the transmission
> >> into reverse and back up several feet. This puts the front axle back
> >> into free-wheeling mode (assuming everything is working properly), and
> >> you can put the transmission into normal gear and drive off.
> >>
> >> If you know the CAD is in this state then you can prepare for towing
> >> simply by putting the transfer case into neutral without starting the
> >> engine (no vacuum). Go ahead and put the transmission into neutral,
> >> hook up to your tow vehicle and go. Some people recommend that you
> >> leave the transmission in gear while towing. Since you have
> >> disconnected the transmission when you put the transfer case in
> >> neutral, this should not be necessary. Further, if the transmission is
> >> in gear and the transfer case is accidently engaged (by a severe bump
> >> maybe?) there will be bad consequences. You don't have to worry about
> >> the transfer case lubrication because the rear output (which is
> >> engaged) also drives the internal oil pump. As long as the CAD is
> >> disengaged you are ready to tow.
> >>
> >> Apparently when I've towed my YJ I been fortunate in that a)I
> >> typically back in to park, therefore I've left the jeep with the CAD
> >> disengaged and b)I normally don't have any reason to start the jeep
> >> prior to putting the transfer case into neutral before hooking it up
> >> to be towed. Since I didn't understand what I was doing, I could very
> >> easily have destroyed my transfer case without knowing why.
> >>
> >> Although I am comfortable with this, knowing how things work, there
> >> are alternatives I discovered as I researched this issue.
> >>
> >> 1)Assuming that the CAD is already disengaged, you can just disconnect
> >> the vacuum line from the CAD box. You'd be fine to start your engine
> >> and move the jeep to the towing vehicle, hook up, put the transfer
> >> case and transmission in neutral and go.
> >>
> >> 2)Install and use a Posi-Lock device instead of the vacuum CAD. Since
> >> you control the front axle lock by cable, you should know the state it
> >> is in.
> >>
> >> 3)Install and use external locking hubs. Not pleasant to use in foul
> >> weather, but again you always know the state of the front axle because
> >> you set it.
> >>
> >> 4)Install a transfer case conversion that gives you a true neutral.
> >> You'd never have to worry about the state of the front axle when you
> >> put the transfer case into neutral then.
> >>
> >> 5)Finally, of course, you can always tow your jeep on a trailer.
> >>
> >> Comments and questions are welcome.
> >>
> >> Your mileage may vary.
> >> Vehicles in mirror are closer than they appear.
> >> Cheers, Ed Humphries
> >> Atlanta, Georgia
> >>
> >
> >
>
>
02-07-2007, 01:58 PM
#46
Guest
Posts: n/a
Re: Flat Tow Wrangler YJ (Informational - Long)
Good discussion on this so far.
I need to note two things:
First, I was researching YJ Wranglers specifically (although we own
and tow a TJ in the same manner).
Second, I see that my original post did not copy in (from the file on
my computer) my "Sources" information. I herewith correct that fault:
Please mentally add the following to the bottom of my orignal post:
Sources:
1. Petersen's 4Wheel & Offroad, How-To, Beefing Up the NP231 Transfer
Case
This article was my first exposure to the internals of how the NP231
works and the first place I read anything about how the vacuum
operated CAD works. Besides the obvious idea of not starting the
engine, this article discusses options 1 and 4 above.
2. Jeep Owner's Bible (Moses Ludel), especially his discussion on how
transfer cases work. Also, although I'd learned about backing up to
disengage the front hubs, this book is the first place I ever saw it
documented.
3. JeepTech, on the web, had a good discussion of the NP231.
4. Many articles I've read in magazines and on the web discuss the
towing limitations of the NP231, although most do not mention the
mechanism of the locking together of the front and rear output shafts
as the culprit. Many articles about Slip Yoke Eliminator (SYE) kits
have some brief information about the rest of the NP231 internals.
5. Novak Adapters, online technical articles.
6. RV Net (and some other RVing sites). Lot's of people flat tow jeeps
and are very willing to share their experiences.
7. Off-Road Adventures (from 4Wheel Parts); an answer to a question in
the Gearhead column actually prompted me to post this note to the
list. Some of what I've said comes from Jim Allen (who obviously
agrees with the other sources I've read). Any errors remain my own.
Further -on comments in this thread-
Frankly I find it hard to believe myself that Jeep would install a
transfer case that would engage the front and rear output shafts
together simply upon you moving the transfer case lever from 2WD to
Neutral! Of course, I don't know why they used chain drive instead of
gear drive either. But in any case, I've read the information about
the output shafts multiple times and from apparently knowledgeable
people. However, this is always in reference to early NP231 units as
installed on YJ Wranglers. I have no idea why this isn't true for TJ's
transfer cases.
Despite my own comments in my original post, I acknowledge that DC
(and earlier owners of Jeep) always say that if you are going to flat
tow to do so with the transmission either in gear (manuals) or in park
(autos). I've not had a problem, nor have others who tow with the
transmission in neutral. I'm not sure what kind of "fluid currents"
would be needed to spin the transmission enough to cause a lubrication
problem. However, I'm willing to stipulate that Jeep knows best in
this regard. Please mentally correct my original post accordingly. In
Gear, that's Clear.
It may have been made clear earlier, but to be complete: it is the
rear output shaft on the NP231 that spins the internal oil pump. The
commercial adaptors that add 2WD-Low to the transfer case (at least
those that result in adding a "true neutral") do not disturb the rear
shaft: it still pumps oil while you flat tow.
So stock YJ and TJ owners can:
Back up about 10 feet in 2WD, drive jeep to tow vehicle and attach,
turn off the engine, place the transfer case in neutral, place the
transmission in gear (or park if auto), proceed to safely tow away.
I'm afraid you CJ owners are left to your own devices. NewJ owners are
expected to follow the instructions found in their spiffy new
manual :-)
Cheers, Ed Humphries
Atlanta, Georgia
I need to note two things:
First, I was researching YJ Wranglers specifically (although we own
and tow a TJ in the same manner).
Second, I see that my original post did not copy in (from the file on
my computer) my "Sources" information. I herewith correct that fault:
Please mentally add the following to the bottom of my orignal post:
Sources:
1. Petersen's 4Wheel & Offroad, How-To, Beefing Up the NP231 Transfer
Case
This article was my first exposure to the internals of how the NP231
works and the first place I read anything about how the vacuum
operated CAD works. Besides the obvious idea of not starting the
engine, this article discusses options 1 and 4 above.
2. Jeep Owner's Bible (Moses Ludel), especially his discussion on how
transfer cases work. Also, although I'd learned about backing up to
disengage the front hubs, this book is the first place I ever saw it
documented.
3. JeepTech, on the web, had a good discussion of the NP231.
4. Many articles I've read in magazines and on the web discuss the
towing limitations of the NP231, although most do not mention the
mechanism of the locking together of the front and rear output shafts
as the culprit. Many articles about Slip Yoke Eliminator (SYE) kits
have some brief information about the rest of the NP231 internals.
5. Novak Adapters, online technical articles.
6. RV Net (and some other RVing sites). Lot's of people flat tow jeeps
and are very willing to share their experiences.
7. Off-Road Adventures (from 4Wheel Parts); an answer to a question in
the Gearhead column actually prompted me to post this note to the
list. Some of what I've said comes from Jim Allen (who obviously
agrees with the other sources I've read). Any errors remain my own.
Further -on comments in this thread-
Frankly I find it hard to believe myself that Jeep would install a
transfer case that would engage the front and rear output shafts
together simply upon you moving the transfer case lever from 2WD to
Neutral! Of course, I don't know why they used chain drive instead of
gear drive either. But in any case, I've read the information about
the output shafts multiple times and from apparently knowledgeable
people. However, this is always in reference to early NP231 units as
installed on YJ Wranglers. I have no idea why this isn't true for TJ's
transfer cases.
Despite my own comments in my original post, I acknowledge that DC
(and earlier owners of Jeep) always say that if you are going to flat
tow to do so with the transmission either in gear (manuals) or in park
(autos). I've not had a problem, nor have others who tow with the
transmission in neutral. I'm not sure what kind of "fluid currents"
would be needed to spin the transmission enough to cause a lubrication
problem. However, I'm willing to stipulate that Jeep knows best in
this regard. Please mentally correct my original post accordingly. In
Gear, that's Clear.
It may have been made clear earlier, but to be complete: it is the
rear output shaft on the NP231 that spins the internal oil pump. The
commercial adaptors that add 2WD-Low to the transfer case (at least
those that result in adding a "true neutral") do not disturb the rear
shaft: it still pumps oil while you flat tow.
So stock YJ and TJ owners can:
Back up about 10 feet in 2WD, drive jeep to tow vehicle and attach,
turn off the engine, place the transfer case in neutral, place the
transmission in gear (or park if auto), proceed to safely tow away.
I'm afraid you CJ owners are left to your own devices. NewJ owners are
expected to follow the instructions found in their spiffy new
manual :-)
Cheers, Ed Humphries
Atlanta, Georgia
02-07-2007, 01:58 PM
#47
Guest
Posts: n/a
Re: Flat Tow Wrangler YJ (Informational - Long)
Good discussion on this so far.
I need to note two things:
First, I was researching YJ Wranglers specifically (although we own
and tow a TJ in the same manner).
Second, I see that my original post did not copy in (from the file on
my computer) my "Sources" information. I herewith correct that fault:
Please mentally add the following to the bottom of my orignal post:
Sources:
1. Petersen's 4Wheel & Offroad, How-To, Beefing Up the NP231 Transfer
Case
This article was my first exposure to the internals of how the NP231
works and the first place I read anything about how the vacuum
operated CAD works. Besides the obvious idea of not starting the
engine, this article discusses options 1 and 4 above.
2. Jeep Owner's Bible (Moses Ludel), especially his discussion on how
transfer cases work. Also, although I'd learned about backing up to
disengage the front hubs, this book is the first place I ever saw it
documented.
3. JeepTech, on the web, had a good discussion of the NP231.
4. Many articles I've read in magazines and on the web discuss the
towing limitations of the NP231, although most do not mention the
mechanism of the locking together of the front and rear output shafts
as the culprit. Many articles about Slip Yoke Eliminator (SYE) kits
have some brief information about the rest of the NP231 internals.
5. Novak Adapters, online technical articles.
6. RV Net (and some other RVing sites). Lot's of people flat tow jeeps
and are very willing to share their experiences.
7. Off-Road Adventures (from 4Wheel Parts); an answer to a question in
the Gearhead column actually prompted me to post this note to the
list. Some of what I've said comes from Jim Allen (who obviously
agrees with the other sources I've read). Any errors remain my own.
Further -on comments in this thread-
Frankly I find it hard to believe myself that Jeep would install a
transfer case that would engage the front and rear output shafts
together simply upon you moving the transfer case lever from 2WD to
Neutral! Of course, I don't know why they used chain drive instead of
gear drive either. But in any case, I've read the information about
the output shafts multiple times and from apparently knowledgeable
people. However, this is always in reference to early NP231 units as
installed on YJ Wranglers. I have no idea why this isn't true for TJ's
transfer cases.
Despite my own comments in my original post, I acknowledge that DC
(and earlier owners of Jeep) always say that if you are going to flat
tow to do so with the transmission either in gear (manuals) or in park
(autos). I've not had a problem, nor have others who tow with the
transmission in neutral. I'm not sure what kind of "fluid currents"
would be needed to spin the transmission enough to cause a lubrication
problem. However, I'm willing to stipulate that Jeep knows best in
this regard. Please mentally correct my original post accordingly. In
Gear, that's Clear.
It may have been made clear earlier, but to be complete: it is the
rear output shaft on the NP231 that spins the internal oil pump. The
commercial adaptors that add 2WD-Low to the transfer case (at least
those that result in adding a "true neutral") do not disturb the rear
shaft: it still pumps oil while you flat tow.
So stock YJ and TJ owners can:
Back up about 10 feet in 2WD, drive jeep to tow vehicle and attach,
turn off the engine, place the transfer case in neutral, place the
transmission in gear (or park if auto), proceed to safely tow away.
I'm afraid you CJ owners are left to your own devices. NewJ owners are
expected to follow the instructions found in their spiffy new
manual :-)
Cheers, Ed Humphries
Atlanta, Georgia
I need to note two things:
First, I was researching YJ Wranglers specifically (although we own
and tow a TJ in the same manner).
Second, I see that my original post did not copy in (from the file on
my computer) my "Sources" information. I herewith correct that fault:
Please mentally add the following to the bottom of my orignal post:
Sources:
1. Petersen's 4Wheel & Offroad, How-To, Beefing Up the NP231 Transfer
Case
This article was my first exposure to the internals of how the NP231
works and the first place I read anything about how the vacuum
operated CAD works. Besides the obvious idea of not starting the
engine, this article discusses options 1 and 4 above.
2. Jeep Owner's Bible (Moses Ludel), especially his discussion on how
transfer cases work. Also, although I'd learned about backing up to
disengage the front hubs, this book is the first place I ever saw it
documented.
3. JeepTech, on the web, had a good discussion of the NP231.
4. Many articles I've read in magazines and on the web discuss the
towing limitations of the NP231, although most do not mention the
mechanism of the locking together of the front and rear output shafts
as the culprit. Many articles about Slip Yoke Eliminator (SYE) kits
have some brief information about the rest of the NP231 internals.
5. Novak Adapters, online technical articles.
6. RV Net (and some other RVing sites). Lot's of people flat tow jeeps
and are very willing to share their experiences.
7. Off-Road Adventures (from 4Wheel Parts); an answer to a question in
the Gearhead column actually prompted me to post this note to the
list. Some of what I've said comes from Jim Allen (who obviously
agrees with the other sources I've read). Any errors remain my own.
Further -on comments in this thread-
Frankly I find it hard to believe myself that Jeep would install a
transfer case that would engage the front and rear output shafts
together simply upon you moving the transfer case lever from 2WD to
Neutral! Of course, I don't know why they used chain drive instead of
gear drive either. But in any case, I've read the information about
the output shafts multiple times and from apparently knowledgeable
people. However, this is always in reference to early NP231 units as
installed on YJ Wranglers. I have no idea why this isn't true for TJ's
transfer cases.
Despite my own comments in my original post, I acknowledge that DC
(and earlier owners of Jeep) always say that if you are going to flat
tow to do so with the transmission either in gear (manuals) or in park
(autos). I've not had a problem, nor have others who tow with the
transmission in neutral. I'm not sure what kind of "fluid currents"
would be needed to spin the transmission enough to cause a lubrication
problem. However, I'm willing to stipulate that Jeep knows best in
this regard. Please mentally correct my original post accordingly. In
Gear, that's Clear.
It may have been made clear earlier, but to be complete: it is the
rear output shaft on the NP231 that spins the internal oil pump. The
commercial adaptors that add 2WD-Low to the transfer case (at least
those that result in adding a "true neutral") do not disturb the rear
shaft: it still pumps oil while you flat tow.
So stock YJ and TJ owners can:
Back up about 10 feet in 2WD, drive jeep to tow vehicle and attach,
turn off the engine, place the transfer case in neutral, place the
transmission in gear (or park if auto), proceed to safely tow away.
I'm afraid you CJ owners are left to your own devices. NewJ owners are
expected to follow the instructions found in their spiffy new
manual :-)
Cheers, Ed Humphries
Atlanta, Georgia
02-07-2007, 01:58 PM
#48
Guest
Posts: n/a
Re: Flat Tow Wrangler YJ (Informational - Long)
Good discussion on this so far.
I need to note two things:
First, I was researching YJ Wranglers specifically (although we own
and tow a TJ in the same manner).
Second, I see that my original post did not copy in (from the file on
my computer) my "Sources" information. I herewith correct that fault:
Please mentally add the following to the bottom of my orignal post:
Sources:
1. Petersen's 4Wheel & Offroad, How-To, Beefing Up the NP231 Transfer
Case
This article was my first exposure to the internals of how the NP231
works and the first place I read anything about how the vacuum
operated CAD works. Besides the obvious idea of not starting the
engine, this article discusses options 1 and 4 above.
2. Jeep Owner's Bible (Moses Ludel), especially his discussion on how
transfer cases work. Also, although I'd learned about backing up to
disengage the front hubs, this book is the first place I ever saw it
documented.
3. JeepTech, on the web, had a good discussion of the NP231.
4. Many articles I've read in magazines and on the web discuss the
towing limitations of the NP231, although most do not mention the
mechanism of the locking together of the front and rear output shafts
as the culprit. Many articles about Slip Yoke Eliminator (SYE) kits
have some brief information about the rest of the NP231 internals.
5. Novak Adapters, online technical articles.
6. RV Net (and some other RVing sites). Lot's of people flat tow jeeps
and are very willing to share their experiences.
7. Off-Road Adventures (from 4Wheel Parts); an answer to a question in
the Gearhead column actually prompted me to post this note to the
list. Some of what I've said comes from Jim Allen (who obviously
agrees with the other sources I've read). Any errors remain my own.
Further -on comments in this thread-
Frankly I find it hard to believe myself that Jeep would install a
transfer case that would engage the front and rear output shafts
together simply upon you moving the transfer case lever from 2WD to
Neutral! Of course, I don't know why they used chain drive instead of
gear drive either. But in any case, I've read the information about
the output shafts multiple times and from apparently knowledgeable
people. However, this is always in reference to early NP231 units as
installed on YJ Wranglers. I have no idea why this isn't true for TJ's
transfer cases.
Despite my own comments in my original post, I acknowledge that DC
(and earlier owners of Jeep) always say that if you are going to flat
tow to do so with the transmission either in gear (manuals) or in park
(autos). I've not had a problem, nor have others who tow with the
transmission in neutral. I'm not sure what kind of "fluid currents"
would be needed to spin the transmission enough to cause a lubrication
problem. However, I'm willing to stipulate that Jeep knows best in
this regard. Please mentally correct my original post accordingly. In
Gear, that's Clear.
It may have been made clear earlier, but to be complete: it is the
rear output shaft on the NP231 that spins the internal oil pump. The
commercial adaptors that add 2WD-Low to the transfer case (at least
those that result in adding a "true neutral") do not disturb the rear
shaft: it still pumps oil while you flat tow.
So stock YJ and TJ owners can:
Back up about 10 feet in 2WD, drive jeep to tow vehicle and attach,
turn off the engine, place the transfer case in neutral, place the
transmission in gear (or park if auto), proceed to safely tow away.
I'm afraid you CJ owners are left to your own devices. NewJ owners are
expected to follow the instructions found in their spiffy new
manual :-)
Cheers, Ed Humphries
Atlanta, Georgia
I need to note two things:
First, I was researching YJ Wranglers specifically (although we own
and tow a TJ in the same manner).
Second, I see that my original post did not copy in (from the file on
my computer) my "Sources" information. I herewith correct that fault:
Please mentally add the following to the bottom of my orignal post:
Sources:
1. Petersen's 4Wheel & Offroad, How-To, Beefing Up the NP231 Transfer
Case
This article was my first exposure to the internals of how the NP231
works and the first place I read anything about how the vacuum
operated CAD works. Besides the obvious idea of not starting the
engine, this article discusses options 1 and 4 above.
2. Jeep Owner's Bible (Moses Ludel), especially his discussion on how
transfer cases work. Also, although I'd learned about backing up to
disengage the front hubs, this book is the first place I ever saw it
documented.
3. JeepTech, on the web, had a good discussion of the NP231.
4. Many articles I've read in magazines and on the web discuss the
towing limitations of the NP231, although most do not mention the
mechanism of the locking together of the front and rear output shafts
as the culprit. Many articles about Slip Yoke Eliminator (SYE) kits
have some brief information about the rest of the NP231 internals.
5. Novak Adapters, online technical articles.
6. RV Net (and some other RVing sites). Lot's of people flat tow jeeps
and are very willing to share their experiences.
7. Off-Road Adventures (from 4Wheel Parts); an answer to a question in
the Gearhead column actually prompted me to post this note to the
list. Some of what I've said comes from Jim Allen (who obviously
agrees with the other sources I've read). Any errors remain my own.
Further -on comments in this thread-
Frankly I find it hard to believe myself that Jeep would install a
transfer case that would engage the front and rear output shafts
together simply upon you moving the transfer case lever from 2WD to
Neutral! Of course, I don't know why they used chain drive instead of
gear drive either. But in any case, I've read the information about
the output shafts multiple times and from apparently knowledgeable
people. However, this is always in reference to early NP231 units as
installed on YJ Wranglers. I have no idea why this isn't true for TJ's
transfer cases.
Despite my own comments in my original post, I acknowledge that DC
(and earlier owners of Jeep) always say that if you are going to flat
tow to do so with the transmission either in gear (manuals) or in park
(autos). I've not had a problem, nor have others who tow with the
transmission in neutral. I'm not sure what kind of "fluid currents"
would be needed to spin the transmission enough to cause a lubrication
problem. However, I'm willing to stipulate that Jeep knows best in
this regard. Please mentally correct my original post accordingly. In
Gear, that's Clear.
It may have been made clear earlier, but to be complete: it is the
rear output shaft on the NP231 that spins the internal oil pump. The
commercial adaptors that add 2WD-Low to the transfer case (at least
those that result in adding a "true neutral") do not disturb the rear
shaft: it still pumps oil while you flat tow.
So stock YJ and TJ owners can:
Back up about 10 feet in 2WD, drive jeep to tow vehicle and attach,
turn off the engine, place the transfer case in neutral, place the
transmission in gear (or park if auto), proceed to safely tow away.
I'm afraid you CJ owners are left to your own devices. NewJ owners are
expected to follow the instructions found in their spiffy new
manual :-)
Cheers, Ed Humphries
Atlanta, Georgia
02-07-2007, 01:58 PM
#49
Guest
Posts: n/a
Re: Flat Tow Wrangler YJ (Informational - Long)
Good discussion on this so far.
I need to note two things:
First, I was researching YJ Wranglers specifically (although we own
and tow a TJ in the same manner).
Second, I see that my original post did not copy in (from the file on
my computer) my "Sources" information. I herewith correct that fault:
Please mentally add the following to the bottom of my orignal post:
Sources:
1. Petersen's 4Wheel & Offroad, How-To, Beefing Up the NP231 Transfer
Case
This article was my first exposure to the internals of how the NP231
works and the first place I read anything about how the vacuum
operated CAD works. Besides the obvious idea of not starting the
engine, this article discusses options 1 and 4 above.
2. Jeep Owner's Bible (Moses Ludel), especially his discussion on how
transfer cases work. Also, although I'd learned about backing up to
disengage the front hubs, this book is the first place I ever saw it
documented.
3. JeepTech, on the web, had a good discussion of the NP231.
4. Many articles I've read in magazines and on the web discuss the
towing limitations of the NP231, although most do not mention the
mechanism of the locking together of the front and rear output shafts
as the culprit. Many articles about Slip Yoke Eliminator (SYE) kits
have some brief information about the rest of the NP231 internals.
5. Novak Adapters, online technical articles.
6. RV Net (and some other RVing sites). Lot's of people flat tow jeeps
and are very willing to share their experiences.
7. Off-Road Adventures (from 4Wheel Parts); an answer to a question in
the Gearhead column actually prompted me to post this note to the
list. Some of what I've said comes from Jim Allen (who obviously
agrees with the other sources I've read). Any errors remain my own.
Further -on comments in this thread-
Frankly I find it hard to believe myself that Jeep would install a
transfer case that would engage the front and rear output shafts
together simply upon you moving the transfer case lever from 2WD to
Neutral! Of course, I don't know why they used chain drive instead of
gear drive either. But in any case, I've read the information about
the output shafts multiple times and from apparently knowledgeable
people. However, this is always in reference to early NP231 units as
installed on YJ Wranglers. I have no idea why this isn't true for TJ's
transfer cases.
Despite my own comments in my original post, I acknowledge that DC
(and earlier owners of Jeep) always say that if you are going to flat
tow to do so with the transmission either in gear (manuals) or in park
(autos). I've not had a problem, nor have others who tow with the
transmission in neutral. I'm not sure what kind of "fluid currents"
would be needed to spin the transmission enough to cause a lubrication
problem. However, I'm willing to stipulate that Jeep knows best in
this regard. Please mentally correct my original post accordingly. In
Gear, that's Clear.
It may have been made clear earlier, but to be complete: it is the
rear output shaft on the NP231 that spins the internal oil pump. The
commercial adaptors that add 2WD-Low to the transfer case (at least
those that result in adding a "true neutral") do not disturb the rear
shaft: it still pumps oil while you flat tow.
So stock YJ and TJ owners can:
Back up about 10 feet in 2WD, drive jeep to tow vehicle and attach,
turn off the engine, place the transfer case in neutral, place the
transmission in gear (or park if auto), proceed to safely tow away.
I'm afraid you CJ owners are left to your own devices. NewJ owners are
expected to follow the instructions found in their spiffy new
manual :-)
Cheers, Ed Humphries
Atlanta, Georgia
I need to note two things:
First, I was researching YJ Wranglers specifically (although we own
and tow a TJ in the same manner).
Second, I see that my original post did not copy in (from the file on
my computer) my "Sources" information. I herewith correct that fault:
Please mentally add the following to the bottom of my orignal post:
Sources:
1. Petersen's 4Wheel & Offroad, How-To, Beefing Up the NP231 Transfer
Case
This article was my first exposure to the internals of how the NP231
works and the first place I read anything about how the vacuum
operated CAD works. Besides the obvious idea of not starting the
engine, this article discusses options 1 and 4 above.
2. Jeep Owner's Bible (Moses Ludel), especially his discussion on how
transfer cases work. Also, although I'd learned about backing up to
disengage the front hubs, this book is the first place I ever saw it
documented.
3. JeepTech, on the web, had a good discussion of the NP231.
4. Many articles I've read in magazines and on the web discuss the
towing limitations of the NP231, although most do not mention the
mechanism of the locking together of the front and rear output shafts
as the culprit. Many articles about Slip Yoke Eliminator (SYE) kits
have some brief information about the rest of the NP231 internals.
5. Novak Adapters, online technical articles.
6. RV Net (and some other RVing sites). Lot's of people flat tow jeeps
and are very willing to share their experiences.
7. Off-Road Adventures (from 4Wheel Parts); an answer to a question in
the Gearhead column actually prompted me to post this note to the
list. Some of what I've said comes from Jim Allen (who obviously
agrees with the other sources I've read). Any errors remain my own.
Further -on comments in this thread-
Frankly I find it hard to believe myself that Jeep would install a
transfer case that would engage the front and rear output shafts
together simply upon you moving the transfer case lever from 2WD to
Neutral! Of course, I don't know why they used chain drive instead of
gear drive either. But in any case, I've read the information about
the output shafts multiple times and from apparently knowledgeable
people. However, this is always in reference to early NP231 units as
installed on YJ Wranglers. I have no idea why this isn't true for TJ's
transfer cases.
Despite my own comments in my original post, I acknowledge that DC
(and earlier owners of Jeep) always say that if you are going to flat
tow to do so with the transmission either in gear (manuals) or in park
(autos). I've not had a problem, nor have others who tow with the
transmission in neutral. I'm not sure what kind of "fluid currents"
would be needed to spin the transmission enough to cause a lubrication
problem. However, I'm willing to stipulate that Jeep knows best in
this regard. Please mentally correct my original post accordingly. In
Gear, that's Clear.
It may have been made clear earlier, but to be complete: it is the
rear output shaft on the NP231 that spins the internal oil pump. The
commercial adaptors that add 2WD-Low to the transfer case (at least
those that result in adding a "true neutral") do not disturb the rear
shaft: it still pumps oil while you flat tow.
So stock YJ and TJ owners can:
Back up about 10 feet in 2WD, drive jeep to tow vehicle and attach,
turn off the engine, place the transfer case in neutral, place the
transmission in gear (or park if auto), proceed to safely tow away.
I'm afraid you CJ owners are left to your own devices. NewJ owners are
expected to follow the instructions found in their spiffy new
manual :-)
Cheers, Ed Humphries
Atlanta, Georgia
02-07-2007, 02:51 PM
#50
Guest
Posts: n/a
Re: Flat Tow Wrangler YJ (Informational - Long)
I did some more looking, and you're right, Earle; at least according to JP
magazine's website at
http://www.jpmagazine.com/howto/154_...ore_cases.html
"Flat tow: If your case is in the stock orientation, remove your rear
driveshaft from the axle and fasten it out of the way. If you've clocked it
flatter than stock, you may get away with the same method mentioned for the
Dana 20. Basically, it needs to have at least one gear on the rear output in
the pool of oil so it slings the oil around when the Jeep is moving. In the
stock clocking setup, this doesn't happen."
They also talk about most or all other tcases in jeeps and what to do with
them.
Pete
"Earle Horton" <apodo@gracioso.usa> wrote in message
news:55adnWQfo-K8i1fYnZ2dnUVZ_qyjnZ2d@comcast.com...
>I am not sure that the Dana 300 will oil itself properly if driven from the
> rear in neutral. You need to get an owner's manual and see what it says.
> An NV4500 upgrade doesn't really change anything in that respect. For
> your
> vehicle disconnecting the rear drive shaft sounds like a good idea.
> Locking
> hubs require you to install a free floating axle, which is a good thing,
> but
> there is the expense.
>
> Earle
>
> "Peter Stolz" <peachyracer@yahoo.com> wrote in message
> news:Lcoyh.3542$4H1.2820@newssvr17.news.prodigy.ne t...
>> OK, so with my '84 CJ, AMC 20, Dana 300, and NV4500, I should put the
> t-case
>> in neutral and put the tranny in a gear. Do I need to disconnect the
>> rear
>> drive shaft? Or, what is the downside of putting locking hubs on the
> rear?
>>
>>
>> "L.W. (Bill) ------ III" <----------@***.net> wrote in message
>> news:52scpuF1o2nm0U1@mid.individual.net...
>> > That's true with the Dana 20 and 300 with only one lever. I would
>> > appreciate it is someone with New Process transfer would confirm this,
> by
>> > simple putting theirs in neutral and jack up a front wheel, if they
> don't
>> > free wheeling hubs and see if you can turn the front driveshaft. I
>> > don't
>> > believe it's true, because this would quickly destroy one of the
>> > differentials.
>> > God Bless America, Bill 0|||||||0
>> > mailto:-------------------- http://www.----------.com/
>> >
>> > <edh3007@bellsouth.net> wrote in message
>> > news:1170785062.593064.102050@v33g2000cwv.googlegr oups.com...
>> >> I have a 1991 Jeep Wrangler YJ with the 2.5L four-cylinder and stock
>> >> five speed manual transmission. I assume it has the standard NP-231
>> >> transfer case.
>> >>
>> >> Although I have successfully flat-towed my YJ (maximum of about 400
>> >> miles one-way and then return about a week later), I've recently
>> >> learned that the NP-231 (at least of this era) does not have a "true"
>> >> neutral position. Instead, while it does uncouple the transmission
>> >> from the transfer case, it also couples the front and rear outputs
>> >> together. If the front axle is engaged this causes gear backlash with
>> >> the potential to destroy the transfer case. If the Center Axle
>> >> Disconnect (CAD) on the front axle is disconnected (disengaged?), then
>> >> the backlash is eliminated.
>> >>
>> >> The problem is that the vacuum operated CAD stays in the last position
>> >> it was put in. If you are preparing your YJ for flat towing and you
>> >> start the engine, the moment you shift the transfer case from 2WD to
>> >> Neutral the vacuum CAD engages the front axle. There you are with the
>> >> outputs of the transfer case locked together and the front axle live
>> >> instead of free-wheeling. Leaving you with the potential of blowing up
>> >> the transfer case.
>> >>
>> >> The standard way to disengage the CAD under normal conditions (i.e.
>> >> you've been in 4WD and are now ready to resume normal 2WD operation)
>> >> is to place the transfer case into 2WD and then put the transmission
>> >> into reverse and back up several feet. This puts the front axle back
>> >> into free-wheeling mode (assuming everything is working properly), and
>> >> you can put the transmission into normal gear and drive off.
>> >>
>> >> If you know the CAD is in this state then you can prepare for towing
>> >> simply by putting the transfer case into neutral without starting the
>> >> engine (no vacuum). Go ahead and put the transmission into neutral,
>> >> hook up to your tow vehicle and go. Some people recommend that you
>> >> leave the transmission in gear while towing. Since you have
>> >> disconnected the transmission when you put the transfer case in
>> >> neutral, this should not be necessary. Further, if the transmission is
>> >> in gear and the transfer case is accidently engaged (by a severe bump
>> >> maybe?) there will be bad consequences. You don't have to worry about
>> >> the transfer case lubrication because the rear output (which is
>> >> engaged) also drives the internal oil pump. As long as the CAD is
>> >> disengaged you are ready to tow.
>> >>
>> >> Apparently when I've towed my YJ I been fortunate in that a)I
>> >> typically back in to park, therefore I've left the jeep with the CAD
>> >> disengaged and b)I normally don't have any reason to start the jeep
>> >> prior to putting the transfer case into neutral before hooking it up
>> >> to be towed. Since I didn't understand what I was doing, I could very
>> >> easily have destroyed my transfer case without knowing why.
>> >>
>> >> Although I am comfortable with this, knowing how things work, there
>> >> are alternatives I discovered as I researched this issue.
>> >>
>> >> 1)Assuming that the CAD is already disengaged, you can just disconnect
>> >> the vacuum line from the CAD box. You'd be fine to start your engine
>> >> and move the jeep to the towing vehicle, hook up, put the transfer
>> >> case and transmission in neutral and go.
>> >>
>> >> 2)Install and use a Posi-Lock device instead of the vacuum CAD. Since
>> >> you control the front axle lock by cable, you should know the state it
>> >> is in.
>> >>
>> >> 3)Install and use external locking hubs. Not pleasant to use in foul
>> >> weather, but again you always know the state of the front axle because
>> >> you set it.
>> >>
>> >> 4)Install a transfer case conversion that gives you a true neutral.
>> >> You'd never have to worry about the state of the front axle when you
>> >> put the transfer case into neutral then.
>> >>
>> >> 5)Finally, of course, you can always tow your jeep on a trailer.
>> >>
>> >> Comments and questions are welcome.
>> >>
>> >> Your mileage may vary.
>> >> Vehicles in mirror are closer than they appear.
>> >> Cheers, Ed Humphries
>> >> Atlanta, Georgia
>> >>
>> >
>> >
>>
>>
>
>
magazine's website at
http://www.jpmagazine.com/howto/154_...ore_cases.html
"Flat tow: If your case is in the stock orientation, remove your rear
driveshaft from the axle and fasten it out of the way. If you've clocked it
flatter than stock, you may get away with the same method mentioned for the
Dana 20. Basically, it needs to have at least one gear on the rear output in
the pool of oil so it slings the oil around when the Jeep is moving. In the
stock clocking setup, this doesn't happen."
They also talk about most or all other tcases in jeeps and what to do with
them.
Pete
"Earle Horton" <apodo@gracioso.usa> wrote in message
news:55adnWQfo-K8i1fYnZ2dnUVZ_qyjnZ2d@comcast.com...
>I am not sure that the Dana 300 will oil itself properly if driven from the
> rear in neutral. You need to get an owner's manual and see what it says.
> An NV4500 upgrade doesn't really change anything in that respect. For
> your
> vehicle disconnecting the rear drive shaft sounds like a good idea.
> Locking
> hubs require you to install a free floating axle, which is a good thing,
> but
> there is the expense.
>
> Earle
>
> "Peter Stolz" <peachyracer@yahoo.com> wrote in message
> news:Lcoyh.3542$4H1.2820@newssvr17.news.prodigy.ne t...
>> OK, so with my '84 CJ, AMC 20, Dana 300, and NV4500, I should put the
> t-case
>> in neutral and put the tranny in a gear. Do I need to disconnect the
>> rear
>> drive shaft? Or, what is the downside of putting locking hubs on the
> rear?
>>
>>
>> "L.W. (Bill) ------ III" <----------@***.net> wrote in message
>> news:52scpuF1o2nm0U1@mid.individual.net...
>> > That's true with the Dana 20 and 300 with only one lever. I would
>> > appreciate it is someone with New Process transfer would confirm this,
> by
>> > simple putting theirs in neutral and jack up a front wheel, if they
> don't
>> > free wheeling hubs and see if you can turn the front driveshaft. I
>> > don't
>> > believe it's true, because this would quickly destroy one of the
>> > differentials.
>> > God Bless America, Bill 0|||||||0
>> > mailto:-------------------- http://www.----------.com/
>> >
>> > <edh3007@bellsouth.net> wrote in message
>> > news:1170785062.593064.102050@v33g2000cwv.googlegr oups.com...
>> >> I have a 1991 Jeep Wrangler YJ with the 2.5L four-cylinder and stock
>> >> five speed manual transmission. I assume it has the standard NP-231
>> >> transfer case.
>> >>
>> >> Although I have successfully flat-towed my YJ (maximum of about 400
>> >> miles one-way and then return about a week later), I've recently
>> >> learned that the NP-231 (at least of this era) does not have a "true"
>> >> neutral position. Instead, while it does uncouple the transmission
>> >> from the transfer case, it also couples the front and rear outputs
>> >> together. If the front axle is engaged this causes gear backlash with
>> >> the potential to destroy the transfer case. If the Center Axle
>> >> Disconnect (CAD) on the front axle is disconnected (disengaged?), then
>> >> the backlash is eliminated.
>> >>
>> >> The problem is that the vacuum operated CAD stays in the last position
>> >> it was put in. If you are preparing your YJ for flat towing and you
>> >> start the engine, the moment you shift the transfer case from 2WD to
>> >> Neutral the vacuum CAD engages the front axle. There you are with the
>> >> outputs of the transfer case locked together and the front axle live
>> >> instead of free-wheeling. Leaving you with the potential of blowing up
>> >> the transfer case.
>> >>
>> >> The standard way to disengage the CAD under normal conditions (i.e.
>> >> you've been in 4WD and are now ready to resume normal 2WD operation)
>> >> is to place the transfer case into 2WD and then put the transmission
>> >> into reverse and back up several feet. This puts the front axle back
>> >> into free-wheeling mode (assuming everything is working properly), and
>> >> you can put the transmission into normal gear and drive off.
>> >>
>> >> If you know the CAD is in this state then you can prepare for towing
>> >> simply by putting the transfer case into neutral without starting the
>> >> engine (no vacuum). Go ahead and put the transmission into neutral,
>> >> hook up to your tow vehicle and go. Some people recommend that you
>> >> leave the transmission in gear while towing. Since you have
>> >> disconnected the transmission when you put the transfer case in
>> >> neutral, this should not be necessary. Further, if the transmission is
>> >> in gear and the transfer case is accidently engaged (by a severe bump
>> >> maybe?) there will be bad consequences. You don't have to worry about
>> >> the transfer case lubrication because the rear output (which is
>> >> engaged) also drives the internal oil pump. As long as the CAD is
>> >> disengaged you are ready to tow.
>> >>
>> >> Apparently when I've towed my YJ I been fortunate in that a)I
>> >> typically back in to park, therefore I've left the jeep with the CAD
>> >> disengaged and b)I normally don't have any reason to start the jeep
>> >> prior to putting the transfer case into neutral before hooking it up
>> >> to be towed. Since I didn't understand what I was doing, I could very
>> >> easily have destroyed my transfer case without knowing why.
>> >>
>> >> Although I am comfortable with this, knowing how things work, there
>> >> are alternatives I discovered as I researched this issue.
>> >>
>> >> 1)Assuming that the CAD is already disengaged, you can just disconnect
>> >> the vacuum line from the CAD box. You'd be fine to start your engine
>> >> and move the jeep to the towing vehicle, hook up, put the transfer
>> >> case and transmission in neutral and go.
>> >>
>> >> 2)Install and use a Posi-Lock device instead of the vacuum CAD. Since
>> >> you control the front axle lock by cable, you should know the state it
>> >> is in.
>> >>
>> >> 3)Install and use external locking hubs. Not pleasant to use in foul
>> >> weather, but again you always know the state of the front axle because
>> >> you set it.
>> >>
>> >> 4)Install a transfer case conversion that gives you a true neutral.
>> >> You'd never have to worry about the state of the front axle when you
>> >> put the transfer case into neutral then.
>> >>
>> >> 5)Finally, of course, you can always tow your jeep on a trailer.
>> >>
>> >> Comments and questions are welcome.
>> >>
>> >> Your mileage may vary.
>> >> Vehicles in mirror are closer than they appear.
>> >> Cheers, Ed Humphries
>> >> Atlanta, Georgia
>> >>
>> >
>> >
>>
>>
>
>