I just put a 3 inch RC lift on my 98 xj. I am getting vibrations between 30 and 40 miles per hour and a horrible clicking vibe out of what seems to be the u joint on deceleration. can 3 degree shims fix my problem?

 

Get a new ujoint and a tc drop until sye. Ihad exact same kit/problem last week

 

What condition are your u-joints in? A worn u-joint will cause clicking, squeaking, and vibrations, especially just after changing something, like installing your lift. If they are not new, go ahead and replace your joints and see if that remedies your problems.