The ones on this Jeep are ST's, not RT/S's which have a 8 out of 10 for
quiet ride:
http://www.goodyeartires.com/goodyea...ion=Laredo+4x4

Whether or not that this about of vibe it related to the slop in the output
bearing of the t-case, I still have a feeling that it is in the front
driveshaft area. This is partly due to the amount of energy in this very
low freq / fairly high displacement vibration. The vibrations are a bit
annoying to the bottoms of my feet... glad I am not ticklish! Actually, it
feels a lot like an old pickup truck that I often had to drive that had
totally worn out U-joints on it, just not that intense. That's why I got
under it and shook the prop shafts - something that I did from time to time
on my ZJ.

All kidding aside, your comment has got me thinking about something I once
read about adding dither noise (dither vibrations). This is the idea of
adding more overall vibrations, just detuned (i.e. white noise) as opposed
to a particular frequency. This is somewhat like the changes made to tires
a long time ago when the manufacturers went to a tread design that didn't
have the same size tread widths all the way around the shoulder. Even
though this example actually reduced noise overall, maybe I can play on the
same theme by adding pseudo-random vibrations with a noisier tread.

I have been told by a DCX mechanic that they went back and forth between
cardin and U joints a few times throughout the WJ's. I am now curious as to
why and when! I think that before I drive another new WJ next week, I'll
get under a few and see if the slop is present in those NV247's as well.


"L.W. (ßill) ------ III" <----------@***.net> wrote in message
news:415A19DC.FE36E8F@***.net...
> The only Goodyear Wranglers with the S and T nomenclature rates a
> six, that's not very good:
>
http://www.tirerack.com/tires/tires....rangler+RT%2FS
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> cr480 wrote:
> >
> > Hm... I hadn't considered that because the Wrangler ST's on it are so
much
> > less truck-ish looking than my ZJ's plain old Wranglers. Tires would
make
> > this kind of vibration worse when under the light acceleration or
> > deceleration load?

 

The ones on this Jeep are ST's, not RT/S's which have a 8 out of 10 for
quiet ride:
http://www.goodyeartires.com/goodyea...ion=Laredo+4x4

Whether or not that this about of vibe it related to the slop in the output
bearing of the t-case, I still have a feeling that it is in the front
driveshaft area. This is partly due to the amount of energy in this very
low freq / fairly high displacement vibration. The vibrations are a bit
annoying to the bottoms of my feet... glad I am not ticklish! Actually, it
feels a lot like an old pickup truck that I often had to drive that had
totally worn out U-joints on it, just not that intense. That's why I got
under it and shook the prop shafts - something that I did from time to time
on my ZJ.

All kidding aside, your comment has got me thinking about something I once
read about adding dither noise (dither vibrations). This is the idea of
adding more overall vibrations, just detuned (i.e. white noise) as opposed
to a particular frequency. This is somewhat like the changes made to tires
a long time ago when the manufacturers went to a tread design that didn't
have the same size tread widths all the way around the shoulder. Even
though this example actually reduced noise overall, maybe I can play on the
same theme by adding pseudo-random vibrations with a noisier tread.

I have been told by a DCX mechanic that they went back and forth between
cardin and U joints a few times throughout the WJ's. I am now curious as to
why and when! I think that before I drive another new WJ next week, I'll
get under a few and see if the slop is present in those NV247's as well.


"L.W. (ßill) ------ III" <----------@***.net> wrote in message
news:415A19DC.FE36E8F@***.net...
> The only Goodyear Wranglers with the S and T nomenclature rates a
> six, that's not very good:
>
http://www.tirerack.com/tires/tires....rangler+RT%2FS
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> cr480 wrote:
> >
> > Hm... I hadn't considered that because the Wrangler ST's on it are so
much
> > less truck-ish looking than my ZJ's plain old Wranglers. Tires would
make
> > this kind of vibration worse when under the light acceleration or
> > deceleration load?

 

The ones on this Jeep are ST's, not RT/S's which have a 8 out of 10 for
quiet ride:
http://www.goodyeartires.com/goodyea...ion=Laredo+4x4

Whether or not that this about of vibe it related to the slop in the output
bearing of the t-case, I still have a feeling that it is in the front
driveshaft area. This is partly due to the amount of energy in this very
low freq / fairly high displacement vibration. The vibrations are a bit
annoying to the bottoms of my feet... glad I am not ticklish! Actually, it
feels a lot like an old pickup truck that I often had to drive that had
totally worn out U-joints on it, just not that intense. That's why I got
under it and shook the prop shafts - something that I did from time to time
on my ZJ.

All kidding aside, your comment has got me thinking about something I once
read about adding dither noise (dither vibrations). This is the idea of
adding more overall vibrations, just detuned (i.e. white noise) as opposed
to a particular frequency. This is somewhat like the changes made to tires
a long time ago when the manufacturers went to a tread design that didn't
have the same size tread widths all the way around the shoulder. Even
though this example actually reduced noise overall, maybe I can play on the
same theme by adding pseudo-random vibrations with a noisier tread.

I have been told by a DCX mechanic that they went back and forth between
cardin and U joints a few times throughout the WJ's. I am now curious as to
why and when! I think that before I drive another new WJ next week, I'll
get under a few and see if the slop is present in those NV247's as well.


"L.W. (ßill) ------ III" <----------@***.net> wrote in message
news:415A19DC.FE36E8F@***.net...
> The only Goodyear Wranglers with the S and T nomenclature rates a
> six, that's not very good:
>
http://www.tirerack.com/tires/tires....rangler+RT%2FS
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> cr480 wrote:
> >
> > Hm... I hadn't considered that because the Wrangler ST's on it are so
much
> > less truck-ish looking than my ZJ's plain old Wranglers. Tires would
make
> > this kind of vibration worse when under the light acceleration or
> > deceleration load?

 

I wonder if adjusting the pinion angle would help? My 2004 WJ also has a low
freq. vibration around 75 MPH and it's done it with two different sets of
properly balanced tires.

On Wed, 29 Sep 2004 21:07:56 -0400, "cr480" <cr480@nomail.com> wrote:

>The ones on this Jeep are ST's, not RT/S's which have a 8 out of 10 for
>quiet ride:
>http://www.goodyeartires.com/goodyea...ion=Laredo+4x4
>
>Whether or not that this about of vibe it related to the slop in the output
>bearing of the t-case, I still have a feeling that it is in the front
>driveshaft area. This is partly due to the amount of energy in this very
>low freq / fairly high displacement vibration. The vibrations are a bit
>annoying to the bottoms of my feet... glad I am not ticklish! Actually, it
>feels a lot like an old pickup truck that I often had to drive that had
>totally worn out U-joints on it, just not that intense. That's why I got
>under it and shook the prop shafts - something that I did from time to time
>on my ZJ.
>
>All kidding aside, your comment has got me thinking about something I once
>read about adding dither noise (dither vibrations). This is the idea of
>adding more overall vibrations, just detuned (i.e. white noise) as opposed
>to a particular frequency. This is somewhat like the changes made to tires
>a long time ago when the manufacturers went to a tread design that didn't
>have the same size tread widths all the way around the shoulder. Even
>though this example actually reduced noise overall, maybe I can play on the
>same theme by adding pseudo-random vibrations with a noisier tread.
>
>I have been told by a DCX mechanic that they went back and forth between
>cardin and U joints a few times throughout the WJ's. I am now curious as to
>why and when! I think that before I drive another new WJ next week, I'll
>get under a few and see if the slop is present in those NV247's as well.
>
>
>"L.W. (ßill) ------ III" <----------@***.net> wrote in message
>news:415A19DC.FE36E8F@***.net...
>> The only Goodyear Wranglers with the S and T nomenclature rates a
>> six, that's not very good:
>>
>http://www.tirerack.com/tires/tires....rangler+RT%2FS
>> God Bless America, ßill O|||||||O
>> mailto:-------------------- http://www.----------.com/
>>
>> cr480 wrote:
>> >
>> > Hm... I hadn't considered that because the Wrangler ST's on it are so
>much
>> > less truck-ish looking than my ZJ's plain old Wranglers. Tires would
>make
>> > this kind of vibration worse when under the light acceleration or
>> > deceleration load?
>

--
Russ Panneton pannetron@hotmail.com
Nederland, CO "Too bad ignorance isn't painful"

 

I wonder if adjusting the pinion angle would help? My 2004 WJ also has a low
freq. vibration around 75 MPH and it's done it with two different sets of
properly balanced tires.

On Wed, 29 Sep 2004 21:07:56 -0400, "cr480" <cr480@nomail.com> wrote:

>The ones on this Jeep are ST's, not RT/S's which have a 8 out of 10 for
>quiet ride:
>http://www.goodyeartires.com/goodyea...ion=Laredo+4x4
>
>Whether or not that this about of vibe it related to the slop in the output
>bearing of the t-case, I still have a feeling that it is in the front
>driveshaft area. This is partly due to the amount of energy in this very
>low freq / fairly high displacement vibration. The vibrations are a bit
>annoying to the bottoms of my feet... glad I am not ticklish! Actually, it
>feels a lot like an old pickup truck that I often had to drive that had
>totally worn out U-joints on it, just not that intense. That's why I got
>under it and shook the prop shafts - something that I did from time to time
>on my ZJ.
>
>All kidding aside, your comment has got me thinking about something I once
>read about adding dither noise (dither vibrations). This is the idea of
>adding more overall vibrations, just detuned (i.e. white noise) as opposed
>to a particular frequency. This is somewhat like the changes made to tires
>a long time ago when the manufacturers went to a tread design that didn't
>have the same size tread widths all the way around the shoulder. Even
>though this example actually reduced noise overall, maybe I can play on the
>same theme by adding pseudo-random vibrations with a noisier tread.
>
>I have been told by a DCX mechanic that they went back and forth between
>cardin and U joints a few times throughout the WJ's. I am now curious as to
>why and when! I think that before I drive another new WJ next week, I'll
>get under a few and see if the slop is present in those NV247's as well.
>
>
>"L.W. (ßill) ------ III" <----------@***.net> wrote in message
>news:415A19DC.FE36E8F@***.net...
>> The only Goodyear Wranglers with the S and T nomenclature rates a
>> six, that's not very good:
>>
>http://www.tirerack.com/tires/tires....rangler+RT%2FS
>> God Bless America, ßill O|||||||O
>> mailto:-------------------- http://www.----------.com/
>>
>> cr480 wrote:
>> >
>> > Hm... I hadn't considered that because the Wrangler ST's on it are so
>much
>> > less truck-ish looking than my ZJ's plain old Wranglers. Tires would
>make
>> > this kind of vibration worse when under the light acceleration or
>> > deceleration load?
>

--
Russ Panneton pannetron@hotmail.com
Nederland, CO "Too bad ignorance isn't painful"

 

I wonder if adjusting the pinion angle would help? My 2004 WJ also has a low
freq. vibration around 75 MPH and it's done it with two different sets of
properly balanced tires.

On Wed, 29 Sep 2004 21:07:56 -0400, "cr480" <cr480@nomail.com> wrote:

>The ones on this Jeep are ST's, not RT/S's which have a 8 out of 10 for
>quiet ride:
>http://www.goodyeartires.com/goodyea...ion=Laredo+4x4
>
>Whether or not that this about of vibe it related to the slop in the output
>bearing of the t-case, I still have a feeling that it is in the front
>driveshaft area. This is partly due to the amount of energy in this very
>low freq / fairly high displacement vibration. The vibrations are a bit
>annoying to the bottoms of my feet... glad I am not ticklish! Actually, it
>feels a lot like an old pickup truck that I often had to drive that had
>totally worn out U-joints on it, just not that intense. That's why I got
>under it and shook the prop shafts - something that I did from time to time
>on my ZJ.
>
>All kidding aside, your comment has got me thinking about something I once
>read about adding dither noise (dither vibrations). This is the idea of
>adding more overall vibrations, just detuned (i.e. white noise) as opposed
>to a particular frequency. This is somewhat like the changes made to tires
>a long time ago when the manufacturers went to a tread design that didn't
>have the same size tread widths all the way around the shoulder. Even
>though this example actually reduced noise overall, maybe I can play on the
>same theme by adding pseudo-random vibrations with a noisier tread.
>
>I have been told by a DCX mechanic that they went back and forth between
>cardin and U joints a few times throughout the WJ's. I am now curious as to
>why and when! I think that before I drive another new WJ next week, I'll
>get under a few and see if the slop is present in those NV247's as well.
>
>
>"L.W. (ßill) ------ III" <----------@***.net> wrote in message
>news:415A19DC.FE36E8F@***.net...
>> The only Goodyear Wranglers with the S and T nomenclature rates a
>> six, that's not very good:
>>
>http://www.tirerack.com/tires/tires....rangler+RT%2FS
>> God Bless America, ßill O|||||||O
>> mailto:-------------------- http://www.----------.com/
>>
>> cr480 wrote:
>> >
>> > Hm... I hadn't considered that because the Wrangler ST's on it are so
>much
>> > less truck-ish looking than my ZJ's plain old Wranglers. Tires would
>make
>> > this kind of vibration worse when under the light acceleration or
>> > deceleration load?
>

--
Russ Panneton pannetron@hotmail.com
Nederland, CO "Too bad ignorance isn't painful"

 

Good question Russ. As planned, I went back to the dealership and went out
for a ride in another new WJ with the service manager who informed me that
everything was in spec. I was unhappy to find that this WJ had the
vibration between 70 and 85 mph as well, but clearly less pronounced. I
then put both that WJ and my WJ in neutral and shook the front driveshafts
where they exit the t-case and we both agreed that there was more slop in
mine by a small amount. He informed me that even so, mine was in spec and
as such could not be submitted for a warranty claim. He wants me to drive
it for another 7000 miles and see what develops.
I find it interesting that DCX would take the "jeep" out of the Grand
Cherokee for next year to make it more car-like when they still buy sloppy
components from suppliers like New Process Gear (or whatever
company/component is causing this vibe). If jeeps become just another SUV
that is car-like, DCX will now have to compete with so many vehicles, some
of which are far more refined. It will be interesting to see if the critics
of the new jeep on this NG are correct.
As for me, I'll give it a year or two to either do something to it that
helps it or trade out of Jeep forever. Man, I wish that I kept my ZJ!

"Russ Panneton" <pannetron@hotmail.com> wrote in message
news:1096509322.R9sCTuWIztYDV/V1jC0D1A@teranews...
> I wonder if adjusting the pinion angle would help? My 2004 WJ also has a
low
> freq. vibration around 75 MPH and it's done it with two different sets of
> properly balanced tires.
> ...
> Russ Panneton pannetron@hotmail.com
> Nederland, CO "Too bad ignorance isn't painful"

 

Good question Russ. As planned, I went back to the dealership and went out
for a ride in another new WJ with the service manager who informed me that
everything was in spec. I was unhappy to find that this WJ had the
vibration between 70 and 85 mph as well, but clearly less pronounced. I
then put both that WJ and my WJ in neutral and shook the front driveshafts
where they exit the t-case and we both agreed that there was more slop in
mine by a small amount. He informed me that even so, mine was in spec and
as such could not be submitted for a warranty claim. He wants me to drive
it for another 7000 miles and see what develops.
I find it interesting that DCX would take the "jeep" out of the Grand
Cherokee for next year to make it more car-like when they still buy sloppy
components from suppliers like New Process Gear (or whatever
company/component is causing this vibe). If jeeps become just another SUV
that is car-like, DCX will now have to compete with so many vehicles, some
of which are far more refined. It will be interesting to see if the critics
of the new jeep on this NG are correct.
As for me, I'll give it a year or two to either do something to it that
helps it or trade out of Jeep forever. Man, I wish that I kept my ZJ!

"Russ Panneton" <pannetron@hotmail.com> wrote in message
news:1096509322.R9sCTuWIztYDV/V1jC0D1A@teranews...
> I wonder if adjusting the pinion angle would help? My 2004 WJ also has a
low
> freq. vibration around 75 MPH and it's done it with two different sets of
> properly balanced tires.
> ...
> Russ Panneton pannetron@hotmail.com
> Nederland, CO "Too bad ignorance isn't painful"

 

Good question Russ. As planned, I went back to the dealership and went out
for a ride in another new WJ with the service manager who informed me that
everything was in spec. I was unhappy to find that this WJ had the
vibration between 70 and 85 mph as well, but clearly less pronounced. I
then put both that WJ and my WJ in neutral and shook the front driveshafts
where they exit the t-case and we both agreed that there was more slop in
mine by a small amount. He informed me that even so, mine was in spec and
as such could not be submitted for a warranty claim. He wants me to drive
it for another 7000 miles and see what develops.
I find it interesting that DCX would take the "jeep" out of the Grand
Cherokee for next year to make it more car-like when they still buy sloppy
components from suppliers like New Process Gear (or whatever
company/component is causing this vibe). If jeeps become just another SUV
that is car-like, DCX will now have to compete with so many vehicles, some
of which are far more refined. It will be interesting to see if the critics
of the new jeep on this NG are correct.
As for me, I'll give it a year or two to either do something to it that
helps it or trade out of Jeep forever. Man, I wish that I kept my ZJ!

"Russ Panneton" <pannetron@hotmail.com> wrote in message
news:1096509322.R9sCTuWIztYDV/V1jC0D1A@teranews...
> I wonder if adjusting the pinion angle would help? My 2004 WJ also has a
low
> freq. vibration around 75 MPH and it's done it with two different sets of
> properly balanced tires.
> ...
> Russ Panneton pannetron@hotmail.com
> Nederland, CO "Too bad ignorance isn't painful"