Author Topic: Rear pinion angle?  (Read 1100 times)

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Offline lokitim

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Rear pinion angle?
« on: March 03, 2013, 08:15:38 AM »
I put an AX15 with SYE in my 93, it runs good but seems to be noisier (vibration?). Jeep has a 4" lift & t/c drop. I know the rear yoke should be clocked up more. How do I figure this, shim size? Or has someone got the same setup & can let me know what shims to use?

Thanks
1993 YJ, 4cyl, AX15 5spd,  J20 3/4 ton axles, SOA with stock springs, disc brakes on all fours, hi-steer, flat tops,33x12.50 General Grabbers on beadlocks,Warn Front Bumper, Smittybilt w/swing away tire mount rear bumper, custom Hi-Lift Mount, Bedliner interior & body sides, Flush mount tail/backups

Offline Jeffy

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Re: Rear pinion angle?
« Reply #1 on: March 03, 2013, 04:13:47 PM »
Do you have a CV or standard joints?  If you have a CV then it's supposed to be inline.  Standard U-joint needs to be set so the upper and lower joints are at the same angle.  2-3* down is OK as drive line torque will move it 2-3* up. 

The best way to set the pinion angle is to re-position the spring perches and perhaps the shock mounts as well.  Shims are OK but I'd be sure to get steel shims as aluminum shims tend to crack if the U-joints are remotely loose.  Shims come in degrees.  Usually 2*, 4*, 6* and 8*.  You need to measure your drivesaft angle and adjust it appropriately.  You could also adjust the pinion angle my adding lift shackles.
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Offline sharpxmen

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Re: Rear pinion angle?
« Reply #2 on: March 04, 2013, 12:55:22 PM »
if you have an SYE and CV driveshaft then get rid of the t-case drop, then like Jeffy said align the diff yoke so it's inline with the driveshaft (or slightly under and not over). If you don't have a CV d/s then i suggest getting one (otherwise it kind of defeating the purpose of getting an SYE.

for setting the angle on a non CV d/s you need your diff yoke at the same angle as your t/case rear output yoke, otherwise you'd get major vibrations, i had the same thing happening when i put a t-case drop and had to change the angle shims).
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Offline Bounty Hunter

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Re: Rear pinion angle?
« Reply #3 on: March 04, 2013, 07:41:57 PM »


Offline lokitim

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Re: Rear pinion angle?
« Reply #4 on: March 06, 2013, 11:33:40 AM »
Thanks, so as I understand, I'll get rid of t/c drop & adjust angle of rear, using shims as I don't have welder, etc. to do much more. (I do have cv shaft)
1993 YJ, 4cyl, AX15 5spd,  J20 3/4 ton axles, SOA with stock springs, disc brakes on all fours, hi-steer, flat tops,33x12.50 General Grabbers on beadlocks,Warn Front Bumper, Smittybilt w/swing away tire mount rear bumper, custom Hi-Lift Mount, Bedliner interior & body sides, Flush mount tail/backups

Offline Bounty Hunter

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Re: Rear pinion angle?
« Reply #5 on: March 06, 2013, 12:22:47 PM »
 Correct. Definitely lose the TC drop.