Jerry Bransford

Part-time 4x4 is a more aggressive system that works better when the
road conditions get really nasty. No matter what, a part-time system
will make sure both your front and rear axles are turning. A full-time
system will not always be able to do that due to how the transfer case
doesn't truly lock the front and rear axles together... they are only
loosely coupled together via a system that may let one end slip and spin
while providing little power to the other end... much like the problem
when one side is spinning and the other side isn't getting enough power
to keep you going.

A part-time system is like having a locker between the front and rear
axles, kind of what a locker inside the axle does for the left and right
tires.

Jerry

Richard wrote:
> this is curious...'(quote the posted article)'...
>
> "Finally, a full-time 4x4 system like comes on most Grand Cherokees and some
> Cherokees and Liberties 'couples' the front and rear axles together, but
> they are not mechanically locked together like a part-time 4wd system does.
> The coupling can be done via either a differential (just like what is
> between the left and right tires) or a fluid (viscous) coupler. The benefit
> to a full-time 4wd system is that because the front and rear axles are not
> mechanically locked together, the front and rear tires/axles can rotate at
> different rpms from each other. This allows a vehicle with a full-time 4wd
> system to drive in 4wd "full time" on a paved road without problem since
> there is no 'wind-up' problem to harm the drivetrain."...
>
> I was driving in some fresh snow today, packed/loose mixed... and as usual,
> I used my "Full Time" 4WD, but I (unusually) was slipping a bit on a very
> steep hill and sharp corners and tried "Part Time" and it seemed to work
> better. So what gives? I thought "Full Time" was supposed to be better. (I
> would never use the "Part Time" on dry pavement)
>
>
> "Jerry Bransford" <jerrypb@***.net> wrote in message
> news:r54Ed.23292$232.5389@fed1read05...
>
>>Here's a brief writeup on a similarly common question I did sometime
>>back, it may be helpful. Click on
>>http://www.jeepforum.com/forum/showthread.php?t=125923
>>
>>Jerry
>>--
>>
>>--
>>Jerry Bransford
>>PP-ASEL N6TAY
>>See the Geezer Jeep at
>>http://members.***.net/jerrypb/
>>Patrick wrote:
>>
>>>Ok i see with the rear wheel not spinning free anymore the other wheel
>
> will
>
>>>lock.
>>>is that it ? Interesting i can't wait to have other reply.
>>>
>>>Thanks
>>>
>>>Pat
>>>"RocknCJ" <jetowle@***.net> a écrit dans le message de news:
>>>7o3Ed.79359$QR1.76872@fed1read04...
>>>
>>>
>>>>Next time try applying the parking brake a bit. This should help kick in
>>>>the limited slip (left/right).
>>>>
>>>>As far as the select trac (front/rear) I am not sure how those transfer
>>>>cases work. I am imagine the parking brake might also help that too.
>>>>My son never had a problem like that in his '94 Grand 5.2l, I am not
>
> sure
>
>>>>if it is the same transfer case.
>>>>
>>>>--James
>>>>
>>>>"Patrick" <pat.guarnaccia@sympatico.ca> wrote in message
>>>>news:i_adnX74-YIyXX3cRVn-3A@b2b2c.ca...
>>>>
>>>>
>>>>>Last night got a bit stuck in a big snow bank, Selectrac I6 4x4, i was
>
> on
>
>>>>>full time
>>>>>
>>>>>The rear right (passenger) wheels was spinning and it feel it was the
>>>>>only wheel really trying to get out, i know the 4x4 is working (Light
>
> on
>
>>>>>and feeling while doing u-turn ) but why i did not see the front wheel
>>>>>spinning while the gc was on Reverse , I was outside with the truck
>>>>>engage looking at the truck spinning. !!!!!
>>>>>
>>>>>I tried part time and no much luck. Got out of there with time and
>>>>>patience REVERSE,DRIVE,REV... Is AWD subaru vehicules working the same
>
> ?
>
>>>>>thanks
>>>>>
>>>>>Pat
>>>>>
>>>>>
>>>>
>>>>
>>>
>
>

--
Jerry Bransford
PP-ASEL N6TAY
See the Geezer Jeep at
http://members.***.net/jerrypb/

Jerry Bransford

Part-time 4x4 is a more aggressive system that works better when the
road conditions get really nasty. No matter what, a part-time system
will make sure both your front and rear axles are turning. A full-time
system will not always be able to do that due to how the transfer case
doesn't truly lock the front and rear axles together... they are only
loosely coupled together via a system that may let one end slip and spin
while providing little power to the other end... much like the problem
when one side is spinning and the other side isn't getting enough power
to keep you going.

A part-time system is like having a locker between the front and rear
axles, kind of what a locker inside the axle does for the left and right
tires.

Jerry

Richard wrote:
> this is curious...'(quote the posted article)'...
>
> "Finally, a full-time 4x4 system like comes on most Grand Cherokees and some
> Cherokees and Liberties 'couples' the front and rear axles together, but
> they are not mechanically locked together like a part-time 4wd system does.
> The coupling can be done via either a differential (just like what is
> between the left and right tires) or a fluid (viscous) coupler. The benefit
> to a full-time 4wd system is that because the front and rear axles are not
> mechanically locked together, the front and rear tires/axles can rotate at
> different rpms from each other. This allows a vehicle with a full-time 4wd
> system to drive in 4wd "full time" on a paved road without problem since
> there is no 'wind-up' problem to harm the drivetrain."...
>
> I was driving in some fresh snow today, packed/loose mixed... and as usual,
> I used my "Full Time" 4WD, but I (unusually) was slipping a bit on a very
> steep hill and sharp corners and tried "Part Time" and it seemed to work
> better. So what gives? I thought "Full Time" was supposed to be better. (I
> would never use the "Part Time" on dry pavement)
>
>
> "Jerry Bransford" <jerrypb@***.net> wrote in message
> news:r54Ed.23292$232.5389@fed1read05...
>
>>Here's a brief writeup on a similarly common question I did sometime
>>back, it may be helpful. Click on
>>http://www.jeepforum.com/forum/showthread.php?t=125923
>>
>>Jerry
>>--
>>
>>--
>>Jerry Bransford
>>PP-ASEL N6TAY
>>See the Geezer Jeep at
>>http://members.***.net/jerrypb/
>>Patrick wrote:
>>
>>>Ok i see with the rear wheel not spinning free anymore the other wheel
>
> will
>
>>>lock.
>>>is that it ? Interesting i can't wait to have other reply.
>>>
>>>Thanks
>>>
>>>Pat
>>>"RocknCJ" <jetowle@***.net> a écrit dans le message de news:
>>>7o3Ed.79359$QR1.76872@fed1read04...
>>>
>>>
>>>>Next time try applying the parking brake a bit. This should help kick in
>>>>the limited slip (left/right).
>>>>
>>>>As far as the select trac (front/rear) I am not sure how those transfer
>>>>cases work. I am imagine the parking brake might also help that too.
>>>>My son never had a problem like that in his '94 Grand 5.2l, I am not
>
> sure
>
>>>>if it is the same transfer case.
>>>>
>>>>--James
>>>>
>>>>"Patrick" <pat.guarnaccia@sympatico.ca> wrote in message
>>>>news:i_adnX74-YIyXX3cRVn-3A@b2b2c.ca...
>>>>
>>>>
>>>>>Last night got a bit stuck in a big snow bank, Selectrac I6 4x4, i was
>
> on
>
>>>>>full time
>>>>>
>>>>>The rear right (passenger) wheels was spinning and it feel it was the
>>>>>only wheel really trying to get out, i know the 4x4 is working (Light
>
> on
>
>>>>>and feeling while doing u-turn ) but why i did not see the front wheel
>>>>>spinning while the gc was on Reverse , I was outside with the truck
>>>>>engage looking at the truck spinning. !!!!!
>>>>>
>>>>>I tried part time and no much luck. Got out of there with time and
>>>>>patience REVERSE,DRIVE,REV... Is AWD subaru vehicules working the same
>
> ?
>
>>>>>thanks
>>>>>
>>>>>Pat
>>>>>
>>>>>
>>>>
>>>>
>>>
>
>

--
Jerry Bransford
PP-ASEL N6TAY
See the Geezer Jeep at
http://members.***.net/jerrypb/

Mike Romain

I believe the big difference is with the full time on, any 'one' of 4
tires can be the main drive wheel, so when stopped and not using the
brakes to vary the load, only one tire can be merrily spinning away.

If you put it into 'part time', the front and rear axles are locked so
when stopped on ice at least 'two' wheels are spinning merrily away.

When this happens, you can hit the brake pedal and with some practice
get both rear wheels spinning and sometimes even all 4 will break loose.

Torque goes to 'both' tires on one differential equally, so the one tire
spinning loose has very little torque on it so the other side sits
still. Hit the brakes or my owners manuals say you can use the
emergency brake and you apply braking torque to the spinning wheel.
This can get strong enough to match the traction of the stopped wheel so
that the wheel on the other side will break loose and spin too.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Patrick wrote:
>
> Last night got a bit stuck in a big snow bank, Selectrac I6 4x4, i was on
> full time
>
> The rear right (passenger) wheels was spinning and it feel it was the only
> wheel really trying to get out, i know the 4x4 is working (Light on and
> feeling while doing u-turn ) but why i did not see the front wheel spinning
> while the gc was on Reverse , I was outside with the truck engage looking at
> the truck spinning. !!!!!
>
> I tried part time and no much luck. Got out of there with time and patience
> REVERSE,DRIVE,REV... Is AWD subaru vehicules working the same ?
>
> thanks
>
> Pat

Mike Romain

I believe the big difference is with the full time on, any 'one' of 4
tires can be the main drive wheel, so when stopped and not using the
brakes to vary the load, only one tire can be merrily spinning away.

If you put it into 'part time', the front and rear axles are locked so
when stopped on ice at least 'two' wheels are spinning merrily away.

When this happens, you can hit the brake pedal and with some practice
get both rear wheels spinning and sometimes even all 4 will break loose.

Torque goes to 'both' tires on one differential equally, so the one tire
spinning loose has very little torque on it so the other side sits
still. Hit the brakes or my owners manuals say you can use the
emergency brake and you apply braking torque to the spinning wheel.
This can get strong enough to match the traction of the stopped wheel so
that the wheel on the other side will break loose and spin too.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Patrick wrote:
>
> Last night got a bit stuck in a big snow bank, Selectrac I6 4x4, i was on
> full time
>
> The rear right (passenger) wheels was spinning and it feel it was the only
> wheel really trying to get out, i know the 4x4 is working (Light on and
> feeling while doing u-turn ) but why i did not see the front wheel spinning
> while the gc was on Reverse , I was outside with the truck engage looking at
> the truck spinning. !!!!!
>
> I tried part time and no much luck. Got out of there with time and patience
> REVERSE,DRIVE,REV... Is AWD subaru vehicules working the same ?
>
> thanks
>
> Pat

Mike Romain

I believe the big difference is with the full time on, any 'one' of 4
tires can be the main drive wheel, so when stopped and not using the
brakes to vary the load, only one tire can be merrily spinning away.

If you put it into 'part time', the front and rear axles are locked so
when stopped on ice at least 'two' wheels are spinning merrily away.

When this happens, you can hit the brake pedal and with some practice
get both rear wheels spinning and sometimes even all 4 will break loose.

Torque goes to 'both' tires on one differential equally, so the one tire
spinning loose has very little torque on it so the other side sits
still. Hit the brakes or my owners manuals say you can use the
emergency brake and you apply braking torque to the spinning wheel.
This can get strong enough to match the traction of the stopped wheel so
that the wheel on the other side will break loose and spin too.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Patrick wrote:
>
> Last night got a bit stuck in a big snow bank, Selectrac I6 4x4, i was on
> full time
>
> The rear right (passenger) wheels was spinning and it feel it was the only
> wheel really trying to get out, i know the 4x4 is working (Light on and
> feeling while doing u-turn ) but why i did not see the front wheel spinning
> while the gc was on Reverse , I was outside with the truck engage looking at
> the truck spinning. !!!!!
>
> I tried part time and no much luck. Got out of there with time and patience
> REVERSE,DRIVE,REV... Is AWD subaru vehicules working the same ?
>
> thanks
>
> Pat

Patrick

So a AWD Subaru would be better for every day driving in the snow ( city
driving )
but very limited off-road ? Is that correct ? i have heard good thing about
Subaru AWD latest generation.

"Mike Romain" <romainm@sympatico.ca> a écrit dans le message de news:
41E15DAF.6B45EE39@sympatico.ca...
>I believe the big difference is with the full time on, any 'one' of 4
> tires can be the main drive wheel, so when stopped and not using the
> brakes to vary the load, only one tire can be merrily spinning away.
>
> If you put it into 'part time', the front and rear axles are locked so
> when stopped on ice at least 'two' wheels are spinning merrily away.
>
> When this happens, you can hit the brake pedal and with some practice
> get both rear wheels spinning and sometimes even all 4 will break loose.
>
> Torque goes to 'both' tires on one differential equally, so the one tire
> spinning loose has very little torque on it so the other side sits
> still. Hit the brakes or my owners manuals say you can use the
> emergency brake and you apply braking torque to the spinning wheel.
> This can get strong enough to match the traction of the stopped wheel so
> that the wheel on the other side will break loose and spin too.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> Patrick wrote:
>>
>> Last night got a bit stuck in a big snow bank, Selectrac I6 4x4, i was on
>> full time
>>
>> The rear right (passenger) wheels was spinning and it feel it was the
>> only
>> wheel really trying to get out, i know the 4x4 is working (Light on and
>> feeling while doing u-turn ) but why i did not see the front wheel
>> spinning
>> while the gc was on Reverse , I was outside with the truck engage looking
>> at
>> the truck spinning. !!!!!
>>
>> I tried part time and no much luck. Got out of there with time and
>> patience
>> REVERSE,DRIVE,REV... Is AWD subaru vehicules working the same ?
>>
>> thanks
>>
>> Pat

Patrick

So a AWD Subaru would be better for every day driving in the snow ( city
driving )
but very limited off-road ? Is that correct ? i have heard good thing about
Subaru AWD latest generation.

"Mike Romain" <romainm@sympatico.ca> a écrit dans le message de news:
41E15DAF.6B45EE39@sympatico.ca...
>I believe the big difference is with the full time on, any 'one' of 4
> tires can be the main drive wheel, so when stopped and not using the
> brakes to vary the load, only one tire can be merrily spinning away.
>
> If you put it into 'part time', the front and rear axles are locked so
> when stopped on ice at least 'two' wheels are spinning merrily away.
>
> When this happens, you can hit the brake pedal and with some practice
> get both rear wheels spinning and sometimes even all 4 will break loose.
>
> Torque goes to 'both' tires on one differential equally, so the one tire
> spinning loose has very little torque on it so the other side sits
> still. Hit the brakes or my owners manuals say you can use the
> emergency brake and you apply braking torque to the spinning wheel.
> This can get strong enough to match the traction of the stopped wheel so
> that the wheel on the other side will break loose and spin too.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> Patrick wrote:
>>
>> Last night got a bit stuck in a big snow bank, Selectrac I6 4x4, i was on
>> full time
>>
>> The rear right (passenger) wheels was spinning and it feel it was the
>> only
>> wheel really trying to get out, i know the 4x4 is working (Light on and
>> feeling while doing u-turn ) but why i did not see the front wheel
>> spinning
>> while the gc was on Reverse , I was outside with the truck engage looking
>> at
>> the truck spinning. !!!!!
>>
>> I tried part time and no much luck. Got out of there with time and
>> patience
>> REVERSE,DRIVE,REV... Is AWD subaru vehicules working the same ?
>>
>> thanks
>>
>> Pat

Patrick

So a AWD Subaru would be better for every day driving in the snow ( city
driving )
but very limited off-road ? Is that correct ? i have heard good thing about
Subaru AWD latest generation.

"Mike Romain" <romainm@sympatico.ca> a écrit dans le message de news:
41E15DAF.6B45EE39@sympatico.ca...
>I believe the big difference is with the full time on, any 'one' of 4
> tires can be the main drive wheel, so when stopped and not using the
> brakes to vary the load, only one tire can be merrily spinning away.
>
> If you put it into 'part time', the front and rear axles are locked so
> when stopped on ice at least 'two' wheels are spinning merrily away.
>
> When this happens, you can hit the brake pedal and with some practice
> get both rear wheels spinning and sometimes even all 4 will break loose.
>
> Torque goes to 'both' tires on one differential equally, so the one tire
> spinning loose has very little torque on it so the other side sits
> still. Hit the brakes or my owners manuals say you can use the
> emergency brake and you apply braking torque to the spinning wheel.
> This can get strong enough to match the traction of the stopped wheel so
> that the wheel on the other side will break loose and spin too.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> Patrick wrote:
>>
>> Last night got a bit stuck in a big snow bank, Selectrac I6 4x4, i was on
>> full time
>>
>> The rear right (passenger) wheels was spinning and it feel it was the
>> only
>> wheel really trying to get out, i know the 4x4 is working (Light on and
>> feeling while doing u-turn ) but why i did not see the front wheel
>> spinning
>> while the gc was on Reverse , I was outside with the truck engage looking
>> at
>> the truck spinning. !!!!!
>>
>> I tried part time and no much luck. Got out of there with time and
>> patience
>> REVERSE,DRIVE,REV... Is AWD subaru vehicules working the same ?
>>
>> thanks
>>
>> Pat

L.W.(=?iso-8859-1?Q?=DFill?=) Hughes III

What have you heard that was good about a Subaru?
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Patrick wrote:
>
> So a AWD Subaru would be better for every day driving in the snow ( city
> driving )
> but very limited off-road ? Is that correct ? i have heard good thing about
> Subaru AWD latest generation.

L.W.(=?iso-8859-1?Q?=DFill?=) Hughes III

What have you heard that was good about a Subaru?
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Patrick wrote:
>
> So a AWD Subaru would be better for every day driving in the snow ( city
> driving )
> but very limited off-road ? Is that correct ? i have heard good thing about
> Subaru AWD latest generation.