William Oliveri

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?

Thanks,

Bill

William Oliveri

Excuse me, That's "Virtually no angle" instead of "Vertically no angle"
below. In other words, almost straight from the pinion to the the angle at
the transfercase.


Bill

"William Oliveri" <wuji@bigvalley.net> wrote in message
news:_eKuc.280$Rp4.193610@monger.newsread.com...
> 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?
>
> Thanks,
>
> Bill
>
>
>

William Oliveri

Excuse me, That's "Virtually no angle" instead of "Vertically no angle"
below. In other words, almost straight from the pinion to the the angle at
the transfercase.


Bill

"William Oliveri" <wuji@bigvalley.net> wrote in message
news:_eKuc.280$Rp4.193610@monger.newsread.com...
> 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?
>
> Thanks,
>
> Bill
>
>
>

William Oliveri

Excuse me, That's "Virtually no angle" instead of "Vertically no angle"
below. In other words, almost straight from the pinion to the the angle at
the transfercase.


Bill

"William Oliveri" <wuji@bigvalley.net> wrote in message
news:_eKuc.280$Rp4.193610@monger.newsread.com...
> 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?
>
> Thanks,
>
> Bill
>
>
>

William Oliveri

Excuse me, That's "Virtually no angle" instead of "Vertically no angle"
below. In other words, almost straight from the pinion to the the angle at
the transfercase.


Bill

"William Oliveri" <wuji@bigvalley.net> wrote in message
news:_eKuc.280$Rp4.193610@monger.newsread.com...
> 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?
>
> Thanks,
>
> Bill
>
>
>

Cherokee-LTD

"William Oliveri" <wuji@bigvalley.net> wrote in message
news:_eKuc.280$Rp4.193610@monger.newsread.com...
: 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.

Maybe, not in every case however. The shims may help for vibration but they
don't compensate for a short shaft (stop giggling).
:
: 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?

Ideally you want the angle of the output shaft the same as the pinion. You
are correct in your statement. The setup you have right now would be ideal
for the SYS/Driveshaft - all of the angle at the output shaft and maybe 1*
at the pinon.

: 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?

In therory, yes but I wouldn't bother too much trying to compensate for
that. Work with an angle finder and fine tune by the seat of your pants for
regular driving.

: Now, the question is, if all this is correct, where to get the shims?

Local spring shops may have an assortment handy. They might let you try a 4*
and exchange it for a 3* etc.
http://www.4crawler.com/4x4/ForSale/Shims.shtml
http://www.djmsuspension.com/Product...inionShims.htm
Any offroad shop wil have them.

: 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?

You may have shims in there now, I can't tell from where I'm sitting. I
would start from the bare spring perch and use one correct shim.

: One more thing, can I (should I) use some washers to adjust the pinion
: temporarily to test this fix?

Not without a camcorder handy... I wanna see this!
The shims are held onto the spring by the cantering pin which goes through
the middle of the shim. If you stacked washers on the pin the only thing you
would achieve is the worlds cheapest lift/lowering block (SOA/SUA). If you
tried to stack them at the front of the perch, they would shoot across the
room as soon as you put weight on the them.

Shackles will also change pinion angle but will affect your amount of lift.

-Brian

Cherokee-LTD

"William Oliveri" <wuji@bigvalley.net> wrote in message
news:_eKuc.280$Rp4.193610@monger.newsread.com...
: 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.

Maybe, not in every case however. The shims may help for vibration but they
don't compensate for a short shaft (stop giggling).
:
: 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?

Ideally you want the angle of the output shaft the same as the pinion. You
are correct in your statement. The setup you have right now would be ideal
for the SYS/Driveshaft - all of the angle at the output shaft and maybe 1*
at the pinon.

: 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?

In therory, yes but I wouldn't bother too much trying to compensate for
that. Work with an angle finder and fine tune by the seat of your pants for
regular driving.

: Now, the question is, if all this is correct, where to get the shims?

Local spring shops may have an assortment handy. They might let you try a 4*
and exchange it for a 3* etc.
http://www.4crawler.com/4x4/ForSale/Shims.shtml
http://www.djmsuspension.com/Product...inionShims.htm
Any offroad shop wil have them.

: 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?

You may have shims in there now, I can't tell from where I'm sitting. I
would start from the bare spring perch and use one correct shim.

: One more thing, can I (should I) use some washers to adjust the pinion
: temporarily to test this fix?

Not without a camcorder handy... I wanna see this!
The shims are held onto the spring by the cantering pin which goes through
the middle of the shim. If you stacked washers on the pin the only thing you
would achieve is the worlds cheapest lift/lowering block (SOA/SUA). If you
tried to stack them at the front of the perch, they would shoot across the
room as soon as you put weight on the them.

Shackles will also change pinion angle but will affect your amount of lift.

-Brian

Cherokee-LTD

"William Oliveri" <wuji@bigvalley.net> wrote in message
news:_eKuc.280$Rp4.193610@monger.newsread.com...
: 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.

Maybe, not in every case however. The shims may help for vibration but they
don't compensate for a short shaft (stop giggling).
:
: 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?

Ideally you want the angle of the output shaft the same as the pinion. You
are correct in your statement. The setup you have right now would be ideal
for the SYS/Driveshaft - all of the angle at the output shaft and maybe 1*
at the pinon.

: 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?

In therory, yes but I wouldn't bother too much trying to compensate for
that. Work with an angle finder and fine tune by the seat of your pants for
regular driving.

: Now, the question is, if all this is correct, where to get the shims?

Local spring shops may have an assortment handy. They might let you try a 4*
and exchange it for a 3* etc.
http://www.4crawler.com/4x4/ForSale/Shims.shtml
http://www.djmsuspension.com/Product...inionShims.htm
Any offroad shop wil have them.

: 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?

You may have shims in there now, I can't tell from where I'm sitting. I
would start from the bare spring perch and use one correct shim.

: One more thing, can I (should I) use some washers to adjust the pinion
: temporarily to test this fix?

Not without a camcorder handy... I wanna see this!
The shims are held onto the spring by the cantering pin which goes through
the middle of the shim. If you stacked washers on the pin the only thing you
would achieve is the worlds cheapest lift/lowering block (SOA/SUA). If you
tried to stack them at the front of the perch, they would shoot across the
room as soon as you put weight on the them.

Shackles will also change pinion angle but will affect your amount of lift.

-Brian

Cherokee-LTD

"William Oliveri" <wuji@bigvalley.net> wrote in message
news:_eKuc.280$Rp4.193610@monger.newsread.com...
: 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.

Maybe, not in every case however. The shims may help for vibration but they
don't compensate for a short shaft (stop giggling).
:
: 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?

Ideally you want the angle of the output shaft the same as the pinion. You
are correct in your statement. The setup you have right now would be ideal
for the SYS/Driveshaft - all of the angle at the output shaft and maybe 1*
at the pinon.

: 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?

In therory, yes but I wouldn't bother too much trying to compensate for
that. Work with an angle finder and fine tune by the seat of your pants for
regular driving.

: Now, the question is, if all this is correct, where to get the shims?

Local spring shops may have an assortment handy. They might let you try a 4*
and exchange it for a 3* etc.
http://www.4crawler.com/4x4/ForSale/Shims.shtml
http://www.djmsuspension.com/Product...inionShims.htm
Any offroad shop wil have them.

: 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?

You may have shims in there now, I can't tell from where I'm sitting. I
would start from the bare spring perch and use one correct shim.

: One more thing, can I (should I) use some washers to adjust the pinion
: temporarily to test this fix?

Not without a camcorder handy... I wanna see this!
The shims are held onto the spring by the cantering pin which goes through
the middle of the shim. If you stacked washers on the pin the only thing you
would achieve is the worlds cheapest lift/lowering block (SOA/SUA). If you
tried to stack them at the front of the perch, they would shoot across the
room as soon as you put weight on the them.

Shackles will also change pinion angle but will affect your amount of lift.

-Brian

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?