I have a 98 Wrangler with a 2" lift running 33" tires.  I know with this set up that it will eat up your driveline and suspension.  I noticed about 6 months ago that my trac bar had loosened up.  I put on a new castle nut and torqued it and placed the cotter pin back.  I had the death wobble reoccur after I installed a new Rusty's Steering upgrade due to a bent draglink.  After test driving it I returned frustrated due to the wobble and realized that the trac bar is loose again.  Does this mean that the ball joint in it is shot?  Plus I have been having an unpredictable popping noise that I haven't been able to 'trac' down?  Is this my possible candidate?
Thanks  

Worn trac bar is high on the list of things to check for when trying to trace down death wobble. Have someone get the jeep rock'n side to side and put your hand on/around the the track bar mounts. There should not be any clicking or movment. Other things to check are ball joints. Lift the tire off the ground and check if any movement when pushed alternately from the top of the tire and then the bottom of the tire. With the jeep on the ground move the steering wheel back and forth lightly. You should notice movement in the tire. If just the steering links are flexing or moving and not the tire, maybe a loose or worn rod end. Tire balance also?? Alignment?? Idealy for 33" tire the caster should be 4-6 not the 6-8 form the factory. That requires adjustable UCAs. And a new steering stabalizer can help as a band-aid. But will probably have a short life if the problem is not found.  

check the wheel bearing also, when they are really bad you'll notice to much camber...

low tire presure will also cause a bad wobble, associated with the caster.

check the sway bar ends, they can cause a popping.  

Just a follow up for anyone interested... I replaced the trac bar with a factory replacement MOOG.  After cutting off the castle nut off I was able to remove the ball joint from the frame I proceeded onto the axle mount.  This I'd love to cuss Chrysler out for continuing to put torx heads on everything.  Well it striped out and never budged.  I ended up using the sawzall to cut the bolt, then ground off the head to the mount.  I was then able to work the trac bar out of it's old location.  I rebolted it up torqued it all down and death wobble gone...  Steering upgrade works great!  Highly recommended to anyone.  

I'm not sure if that's great, or sorry for your misery. I feel your pain... sometimes why can't two bolts really be "I'll be done in 10 minutes dear". Elaborate on your steering upgrade. What's the big difference from original? You got the Rusty's wheel to wheel tie rod right? That's what Mud has too. He also says way cool.  

I guess the big part is that they are not bent like the ones I had taken off.  They are more parallel to each other which makes the steering less binding on and off road.  Much more heavy duty than oem, but use stock tie rod ends which is nice and easy to find if needed.  It's just a nice piece of equipment, I guess if I replaced the old worn out ones with anything new I would be happy also.  I'm just looking forward to this set up not bending as easy as before...  

Ok, just started getting death wobble here too.  TJ w/ 7" l/a lift and Rockkrawler upgraded steering.  My old ARG box was whooped, so replaced it w/ PSC x-treme box and a new tie rod end @ the pitman arm.  Those were the only two origional parts from before the lift.  All new suspension parts and axles.  Alignment is pretty good, running 33X12.5 TSL's.  Balance on them is OK, like I said they're TSL's.  Would a steering stabilizer give me the upper hand here?  Maybe re-balance?  Any help would be great!!  

check the tire presure, those tsls could only have 10 psi in em without  bulging. the stabilizer may help, It's just hardly ever the only problem.  

What caster angle are you running? What does "Alignment is pretty good" mean? It sounds like you're running the same setup before your death wobble problem with the exception of a box and a rod end on the pitman arm. Is that true? If so I would be looking at alignment. Also, I have had death wobble appear with a tire rotaion. Put the tires back, and death wobble gone. Try to keep the tires with the least amount of balance weight on the front.  

Ok, found my problem!!!  Don't know how I never noticed it before.  If you are not familiar with the Rock Krawler steering upgrade, you bore out the taper on your spindles to accept a 5/8" bolt for your heim joints.  The Heim joint for you tie rod is on top and the one for the drag link is on the bottom of the knuckle.  The bottom is a high misalignment type with the extensions on the ball.  Well, those little extensions compressed letting some slop and started elongating the hole for the bolt. Measured it to be only .015", but it was enough. Bent up some shim stock out of .008". Now it's a press fit and everything work fine!!!  A couple hours and quite a few beers had this one figured out. Thanks for the help!!!  

have another beer!  

I have a 99 Jeep wrangler with a 4 inch suspension lift and 2 1/4 inch coil spring spacers, with 35 inch tires and i too also have the same problem with the death wobble. I got a brand new track bar to reach the 2 extra inches and then got my jeep alignment redone and i still have the death wobble. Any help or advice to fix the problem...  

You don't have to tell me twice!!!!  Sorry but the lol thing is kina gay for me. Anyway,
Ben, which is my name too... not too hard to figure out. What tires are you running? How long has it been since they've been balanced? Try a rotation and see if it goes away. I have heard of warped rotors doing it, but I think thats a stretch. Is you p/s box sloppy in the least? In short, unbalanced tires and any play whatsoever in your steering assy. is your enemy.  

did anyone do any drilling on the trac bar bracket? cause when i put my adjustable trac bar in, it required drilling. I GOT A HELL OF A WOBBLE and it loosened my bar every time. so, to solve that problem, i cut the bottom part of the bracket out. got some 1in square stock, drilled a 9/16 hole in it, "centered", and welded it. that bar is not going anywhere.

also, check your bushing on the lower end of the trac bar, it may be worn out.

POPPING- yes, i have it to. its probably your gear box. it gets loos. the bolts from factory are not loc-tighted in. take the bolts out, put some loc-tight on, and re-install. that should get rid of your pop.  

I have the same problem, just found it the other day. I drive a 99' TJ with a three inch bds suspension lift and 31.5x10.5 tires. I just had my tires rotated and balanced, had an alignment done right after i put the liftkit on and still have the wobble. It only accurs over 50 mph and only in one spot on a nearby road. There are two bumps back to back in the road and it is an off-ramp so im normally doing 55 when i hit the bumps, it begins to wobble then progressivly gets worse and doesnt stop until i slow down to 10-15 mph. I think my steering stabalizer is worn out but it is only 6 months old so it seems like that might not be the source of the problem. If anyone has any suggestions please let me know, ive read a bunch of stuff here and it has helped but anything different will be much appreciated.