Steve

Hi,

1. Drop the tcase xmember 3/4".

2. Put the Jeep on a level surface with normal load inside.

3. Use an angle finder on the slip yoke to measure the tcase output
shaft angle.

4. Measure the pinion angle. Back of the diff housing makes a good
perpendicular surface for the angle finder.

5. Subtract your tcase angle from your pinion angle. This is exactly how
many degrees you need to drop the pinion. If you round it off, round up
to account for axle wrap.

6. Figure out what your drive shaft angle will be relative to the pinion
& tcase once they are parallel. If this relative angle is greater than
15 degrees, you'll have trouble eliminating vibes and your joints will
wear quickly.

Beg or borrow shims from local Jeep club/garage or buy new:

http://www.rubiconexpress.com/dynami...p?folderid=229

Depending on the depth of the shims, you may also need center pins with
longer nubs.

Better yet, cut your spring perches off and re-weld them for precisely
the angle you want.

Steve

William Oliveri wrote:
> After reading a couple of articles on resolving driveshaft vibration it
> seems I can get away with using shims rather than getting a CV Shaft if I
> understand it correctly.
>
> After adding my lift kit my shaft has an angle coming down from the transfer
> case but has vertically no angle at the pinion so the fix, it would seem,
> would be to shim the pinion down to match the angle at the transfercase. Is
> this correct?
>
> Also from my reading it appears that the pinion tilts up when driving so I
> would need to compensate additionally downward when shimming. Also correct?
>
> Now, the question is, if all this is correct, where to get the shims?
>
> Also, the rear leaf springs already have shims attached in some way. Do I
> need to take these off or just apply the compensating shims?
>
> One more thing, can I (should I) use some washers to adjust the pinion
> temporarily to test this fix?

Steve

Hi,

1. Drop the tcase xmember 3/4".

2. Put the Jeep on a level surface with normal load inside.

3. Use an angle finder on the slip yoke to measure the tcase output
shaft angle.

4. Measure the pinion angle. Back of the diff housing makes a good
perpendicular surface for the angle finder.

5. Subtract your tcase angle from your pinion angle. This is exactly how
many degrees you need to drop the pinion. If you round it off, round up
to account for axle wrap.

6. Figure out what your drive shaft angle will be relative to the pinion
& tcase once they are parallel. If this relative angle is greater than
15 degrees, you'll have trouble eliminating vibes and your joints will
wear quickly.

Beg or borrow shims from local Jeep club/garage or buy new:

http://www.rubiconexpress.com/dynami...p?folderid=229

Depending on the depth of the shims, you may also need center pins with
longer nubs.

Better yet, cut your spring perches off and re-weld them for precisely
the angle you want.

Steve

William Oliveri wrote:
> After reading a couple of articles on resolving driveshaft vibration it
> seems I can get away with using shims rather than getting a CV Shaft if I
> understand it correctly.
>
> After adding my lift kit my shaft has an angle coming down from the transfer
> case but has vertically no angle at the pinion so the fix, it would seem,
> would be to shim the pinion down to match the angle at the transfercase. Is
> this correct?
>
> Also from my reading it appears that the pinion tilts up when driving so I
> would need to compensate additionally downward when shimming. Also correct?
>
> Now, the question is, if all this is correct, where to get the shims?
>
> Also, the rear leaf springs already have shims attached in some way. Do I
> need to take these off or just apply the compensating shims?
>
> One more thing, can I (should I) use some washers to adjust the pinion
> temporarily to test this fix?

Steve

Hi,

1. Drop the tcase xmember 3/4".

2. Put the Jeep on a level surface with normal load inside.

3. Use an angle finder on the slip yoke to measure the tcase output
shaft angle.

4. Measure the pinion angle. Back of the diff housing makes a good
perpendicular surface for the angle finder.

5. Subtract your tcase angle from your pinion angle. This is exactly how
many degrees you need to drop the pinion. If you round it off, round up
to account for axle wrap.

6. Figure out what your drive shaft angle will be relative to the pinion
& tcase once they are parallel. If this relative angle is greater than
15 degrees, you'll have trouble eliminating vibes and your joints will
wear quickly.

Beg or borrow shims from local Jeep club/garage or buy new:

http://www.rubiconexpress.com/dynami...p?folderid=229

Depending on the depth of the shims, you may also need center pins with
longer nubs.

Better yet, cut your spring perches off and re-weld them for precisely
the angle you want.

Steve

William Oliveri wrote:
> After reading a couple of articles on resolving driveshaft vibration it
> seems I can get away with using shims rather than getting a CV Shaft if I
> understand it correctly.
>
> After adding my lift kit my shaft has an angle coming down from the transfer
> case but has vertically no angle at the pinion so the fix, it would seem,
> would be to shim the pinion down to match the angle at the transfercase. Is
> this correct?
>
> Also from my reading it appears that the pinion tilts up when driving so I
> would need to compensate additionally downward when shimming. Also correct?
>
> Now, the question is, if all this is correct, where to get the shims?
>
> Also, the rear leaf springs already have shims attached in some way. Do I
> need to take these off or just apply the compensating shims?
>
> One more thing, can I (should I) use some washers to adjust the pinion
> temporarily to test this fix?