so ive been noticing some vibes starting to show them selves, ive got a 4.5 inch lift and it vibed really bad until i got a drop crossmember, then smooth as glass, but now they are starting to return, my first thought was u-joints, but i checked all them, no play in the rear driveshaft and a little in the front, but its always been that way as long as ive owned the jeep, the rear driveshaft isnt missing any weights either so its not unbalanced, i cant figure out why its vibrating now

 

check the u-joints on your rear drive shaft. U-joints have a memory (for lack of a better term), they wear in at a certain angle and will tend to vibe funny when their normal angle changes. So you do the lift and everything feels good untill the u-joints start wearing differently than they are used too. It's a cheap fix and a good place to start.

 

yeah i wasnt too worried about having to replace any u joints, they are cheap and easy, ill probably go ahead and replace them anyways