Warlock13

rear uppers only right

Piginajeep

rear uppers will fix your problem, you can always add adjustable lowers if you want.

wayoflife

yes, all you need are the rear uppers.

blazer4949

I have the rear upper adjustable control arms and still have the vibration.
So I can assume the alignment is wrong? The installers failed to set
the correct length for the control arms?

Big A

I am going to be replacing all my control arms with Currie's, And hope i dont have these issues... I will be following this thread, As i have the same lift going on soon...

chuck45

Just putting adjustable arms on won't cure the problem. They have to be adjusted so that the pinion angle is proper. The shop may have gotten lazy and just adjusted them to duplicate stock lengthand threw them on. Get an angle gauge and use it on the flats on the axle and the driveshaft. They want to be within 1 degree plus or minus. In essence the the pinion shaft wants to be pointing at the upper ujoints in a line fairly parallel with the driveshaft. (Factory driveshfts split the difference and are much more tolerant of being out of wack.) Then you have to drive it and see how your setup feels. To get mine smooth I had to go 1 turn of the control arm adjustments but i forget in which direction.

chuck45

This has an article by Tom Woods and has a couple of diagrams showing what you want as far as pinion angle:

http://www.quadratec.com/jeep_knowle.../article-3.htm

If the shop set it up as in the top pic instead of the bottom you'd surely have trouble.