I have an '88 Cherokee 4x4 and the DW began in mine shortly after I got it (sure is exciting at freeway speeds ain't it!).
This is what worked for me:
I put on a new 3" Rancho lift, the wobble lessened. Put on a bigger damper, a bit less wobble. Got all new 31" tires on Enkei rims, much less wobble. Got the front aligned (the steering pulled to the right), no more wobble and more importantly, it looks real cool with the big tires, rims and lift.
The alignment is off again and I can feel a bit of the wobble, plus I have a couple of worn and loose tie rod ends so they will all get replaced and a new alignment.
But it is a fun way to scare the crap out your passengers and get them swearing they will never ride with you again and talk about how insane you are and why would anyone ever want to own, much less drive, one of these beasts when you could get a perfectly good Xterra (I'm pretty sure that's an oxymoron) and on and on and on...
it's a Jeep thang