Lift a little higher than expected. Question.

I did a Rustys 3" with a full leaf back.

In the end, I got 3.5 in the front and 4" in the rear. I did NOT do a TC drop from reading the forums that it isnt needed for 3 inches and under. I have a slight vibe at low speed, and by low I mean 15mph and under. The worst it ever is is when pulling away from a stop light.

Its been about 300 miles or so now, and I wanted to see if it would settle any before dropping the TC. It still has the vibe. Would you give it a little longer or do I need to go ahead and do it before I wear something out. Its still at 4 inches in the rear.

Its a 91' if that matters. Also, I have not used 4WD yet.

300 miles isnt much. put some heavy stuff in the back to help it settle. when you drop the TC, you will need some degree shims to get the correct pinion angle to prevent vibes.

What does the pinion angle look like now? Are the u-joints old as hell?

1990JEEPXJ said:

300 miles isnt much. put some heavy stuff in the back to help it settle. when you drop the TC, you will need some degree shims to get the correct pinion angle to prevent vibes.

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Well thats good to know. I just assumed it would be a square drop.

I have to haul about 400 lbs of files to the lake to burn this weekend. That might do the trick.

lowrange2 said:

What does the pinion angle look like now? Are the u-joints old as hell?

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144k miles. If that old or not is anyones guess.

If anything get some washers that will fit the bolts for the cross member, adda few and see if it goes away. Yes, pinion angle and u-joints are a factor, but if they are good or close then the washers should work.

I had this issue with my 96 with a 3.5" lift. I adjusted my axle with shims first (in the front, to pivot the axle pinion back down). The vibe was almost gone. Then, I added about 3/8" with three washers as suggeste above. Vibe gone. Some do the T-case first, but my local Jeep driveline guy told me the opposite. Saves on ground clearance. The obvious and best fix is an SYE and new driveshaft though. Mine is a quick fix until I can afford the SYE setup.

lowrange2 said:

What does the pinion angle look like now? Are the u-joints old as hell?

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This.

Check your pinion angle--a few degrees of shims may be all you need.