Re: Pinion angle, revisited...
 

Did you ever unhook the front driveshaft as was mentioned? Vibrations
can come from sneaky places.....

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

Nathan Otis wrote:
>
> Ok, I got under the TJ and dropped the pinion a little (adjusting the UCAs
> accordingly). I still have vibration at 55+. This weekend I'll probably drop
> it a little more to see if that does the trick... I guess the option is put
> spacers on the t-case skid, but it doesn't seem like I should have to what
> with the CV shaft and all...
>
> Is there something I'm missing?
> n.

Re: Pinion angle, revisited...
 

Did you ever unhook the front driveshaft as was mentioned? Vibrations
can come from sneaky places.....

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

Nathan Otis wrote:
>
> Ok, I got under the TJ and dropped the pinion a little (adjusting the UCAs
> accordingly). I still have vibration at 55+. This weekend I'll probably drop
> it a little more to see if that does the trick... I guess the option is put
> spacers on the t-case skid, but it doesn't seem like I should have to what
> with the CV shaft and all...
>
> Is there something I'm missing?
> n.

Re: Pinion angle, revisited...
 

Mike,

It seems counter intuitive that the vibes would be coming from the front,
because 1. I haven't changed anything in the front and 2. I had to drive in
4hi with no rear shaft for a while and there were no vibes during that time
so 3. why would there be a problem in the front all of a sudden?

Still, if I can't get rid of it with control arm adjustments tomorrow
morning, I'll try pulling the front shaft for kicks. Thanks for the tip.
n.


"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4231A7F0.3DD13585@sympatico.ca...
> Did you ever unhook the front driveshaft as was mentioned? Vibrations
> can come from sneaky places.....
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> Nathan Otis wrote:
>>
>> Ok, I got under the TJ and dropped the pinion a little (adjusting the
>> UCAs
>> accordingly). I still have vibration at 55+. This weekend I'll probably
>> drop
>> it a little more to see if that does the trick... I guess the option is
>> put
>> spacers on the t-case skid, but it doesn't seem like I should have to
>> what
>> with the CV shaft and all...
>>
>> Is there something I'm missing?
>> n.

Re: Pinion angle, revisited...
 

Mike,

It seems counter intuitive that the vibes would be coming from the front,
because 1. I haven't changed anything in the front and 2. I had to drive in
4hi with no rear shaft for a while and there were no vibes during that time
so 3. why would there be a problem in the front all of a sudden?

Still, if I can't get rid of it with control arm adjustments tomorrow
morning, I'll try pulling the front shaft for kicks. Thanks for the tip.
n.


"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4231A7F0.3DD13585@sympatico.ca...
> Did you ever unhook the front driveshaft as was mentioned? Vibrations
> can come from sneaky places.....
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> Nathan Otis wrote:
>>
>> Ok, I got under the TJ and dropped the pinion a little (adjusting the
>> UCAs
>> accordingly). I still have vibration at 55+. This weekend I'll probably
>> drop
>> it a little more to see if that does the trick... I guess the option is
>> put
>> spacers on the t-case skid, but it doesn't seem like I should have to
>> what
>> with the CV shaft and all...
>>
>> Is there something I'm missing?
>> n.

Re: Pinion angle, revisited...
 

Mike,

It seems counter intuitive that the vibes would be coming from the front,
because 1. I haven't changed anything in the front and 2. I had to drive in
4hi with no rear shaft for a while and there were no vibes during that time
so 3. why would there be a problem in the front all of a sudden?

Still, if I can't get rid of it with control arm adjustments tomorrow
morning, I'll try pulling the front shaft for kicks. Thanks for the tip.
n.


"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4231A7F0.3DD13585@sympatico.ca...
> Did you ever unhook the front driveshaft as was mentioned? Vibrations
> can come from sneaky places.....
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> Nathan Otis wrote:
>>
>> Ok, I got under the TJ and dropped the pinion a little (adjusting the
>> UCAs
>> accordingly). I still have vibration at 55+. This weekend I'll probably
>> drop
>> it a little more to see if that does the trick... I guess the option is
>> put
>> spacers on the t-case skid, but it doesn't seem like I should have to
>> what
>> with the CV shaft and all...
>>
>> Is there something I'm missing?
>> n.

Re: Pinion angle, revisited...
 

Nathan Otis wrote:
> Well.... That sounds _pretty_ percise ;-)
>

You don't want to have any one universal joint not making enough bend-
you'll get vibration (from the shaft going into an orbit) and short
u-joint life (if the joint isn't bending far enough then the grease
isn't able to do its job, it gets squeezed between all the needles and
the needles beat dents into the cap and trunion.

IIRC, Spicer recommends a minimum 7 deg. angle to ensure grease
distribution.

Also, if you drove this for some time with the rear shaft out, check
that bearing in the transfer case- the output shaft might have been
hammering the bearing due to the lack of load.

I take it you've got a new rear shaft there, are the yokes aligned?

John

Re: Pinion angle, revisited...
 

Nathan Otis wrote:
> Well.... That sounds _pretty_ percise ;-)
>

You don't want to have any one universal joint not making enough bend-
you'll get vibration (from the shaft going into an orbit) and short
u-joint life (if the joint isn't bending far enough then the grease
isn't able to do its job, it gets squeezed between all the needles and
the needles beat dents into the cap and trunion.

IIRC, Spicer recommends a minimum 7 deg. angle to ensure grease
distribution.

Also, if you drove this for some time with the rear shaft out, check
that bearing in the transfer case- the output shaft might have been
hammering the bearing due to the lack of load.

I take it you've got a new rear shaft there, are the yokes aligned?

John

Re: Pinion angle, revisited...
 

Nathan Otis wrote:
> Well.... That sounds _pretty_ percise ;-)
>

You don't want to have any one universal joint not making enough bend-
you'll get vibration (from the shaft going into an orbit) and short
u-joint life (if the joint isn't bending far enough then the grease
isn't able to do its job, it gets squeezed between all the needles and
the needles beat dents into the cap and trunion.

IIRC, Spicer recommends a minimum 7 deg. angle to ensure grease
distribution.

Also, if you drove this for some time with the rear shaft out, check
that bearing in the transfer case- the output shaft might have been
hammering the bearing due to the lack of load.

I take it you've got a new rear shaft there, are the yokes aligned?

John