Death Wobble, need advice to find cause
 

Have a 98 grand cherokee laredo, 5.2 auto, rear wheel drive, 94k miles. Death wobble used to be infrequent but over time has gotten worse. Replaced every suspension part as well as rotors and pads. New tires all around and alignment but it still shows up when hitting a bump at high speeds. Dropped air pressure down to 29 psi as I have seen recommended on various sites but I can not get rid of it. Replaced all 4 ball joints, stabilizer bushings and struts, tie rod ends and bars, steering stabilizer shock as well as front shocks, contol arm bushings and whatever else is down there. Everything but the steering box that has no play and is securely mounted. All I have left is the front bearing assemblys and they seem fine. Any Suggestions? Oh one more thing. It is completely stock. Not raised or after marketed at all.

Have you replaced the track bar?

Yes the track bar also. Every darn part is new. I am sure there are no wear on any of the suspension parts. It seems this is a common occurence with Jeep front ends. Suprised they don't improve the design. Been reading where the alignment is very sensitive. Are there any known settings that work best?

Check the tightness of your track bar. Check the tightness of you lower control arms. Any little bit of movement will contribute to DW. If they are OK add a little caster. That is what I did to cure mine, and I have 3 1/2" of lift.
Hope this helps,
Mike

TB hole can be wore out of round.

what size tires you running toe is very important settting it at zero difference from front to rear might help

Is there any kind of lift on your rig?

There is no lift and the tires are p225/75 15. Changed the old tires with less then 50% wear as the garage told me it was the tires.

Try balance beads I had a slight wobble after like you did replaced all but wheel bearings, it took it away.:yes:

This might sound strange and is kind of a long shot, but I had the same problem happen to me. Over time it got worse and worse, then I realized I hadn't had a tune up in a while. Short story, one of the spark plugs/wiring harness was bad and hitting a bump caused it to misfire, causing a horrible wobble. Since I did the tune up haven't had any problems with it. Took the longest time for the sensor to actually go off saying there was a misfire. If you haven't resolved it already, I'd try to replace the distributor cap, wiring harness and spark plugs.