OK. So I have been trying to deal with this for the past few months and haven't figured it out yet. Last summer I put a 2.5 inch lift on my 08 unlimited. Had death wobble. But only at highway speeds and hitting a substantial sized bump. I did the alignment at my buddy's shop and the dw is now gone thank god. But I have a slight wobble at 55mph and the Heep feels flighty. When I hit the brakes at 55 it gets worse and almost feels like dw but it stops when I let off the brakes. I have no idea what this could be. And it only happens at 55! If I hit the brakes at 70 no wobble until I get to 55. I got a new skyjacker stabilizer when I put the lift on. I'm beginning to get demoralized! Somebody help please!

 

Do a search for something like "ball joints" tons of info. From what I have gathered you could have a problem with you ball joints, front track bar, wheel balancing, and\or alignment. I know you said you already got an alignment but I would check out the ball joints and track bar if I were you.

 

What parts did your lift consist of?

 

Coils shocks new bump stops and a rear track bar bracket.