My 97 xj gets DW but only after hitting a bump on the highway. I was driving home yesterday and hit a bump on the highway and it sent me into a violent death wobble. I have a rc 4.5" lift with a rubicon adjustable track bar and drop bracket. I also just replaced the TRE at the pitman. I am stumped on what would cause me to wobble but only after a bump is hit at high speed.

Didn't we just have this thread?

Ball joints, badly adjusted track bar, loose trackbar bracket, worn TRE's, control arm bushings. Technically the steering box, too but it's pretty rare for that to actually be the source unless DW has been allowed to go on too long at some point in the past. You have to visually inspect everything. Preferably with a friend to turn it lock-to-lock for you while you watch for anything misbehaving.

The bump just gives whatever's worn the opportunity it needs. The more times that happens the worse it'll get and the easier it'll be to happen again. Not to mention it's real damn hard on anything you have that's not already worn out including your tires.

I sometimes hesitate to regurgitate my "cut and paste" answer on death wobble, but it holds up as the root causes are almost always the same. You have some work ahead of you; lifts do add another variable to the equation. I have been able to solve DW quickly and other times it has been extremely difficult. Good luck and keep us updated!
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My understanding of “death wobble” is this. Somewhere on the vehicle, one or more components is worn beyond tolerances, and when oscillation initiates from a suspension “traumatic” event (like hitting a bump or a pothole) or also when a vibration reaches a certain point and harmonic at a certain speed, it causes the other components to react. This is called the “multiplier effect”, where one component affects one or more other components as the event travels through the front end of the vehicle.

Death wobble is not uncommon with the XJ! It is even more common with a lifted XJ. Finding the worn component or components is not always easy and can sometimes be downright difficult. Sometimes it’s obvious, other times everything appears to be okay when you perform an inspection on a hoist, but getting the vehicle up in the air and going over everything with a fine tough comb is always a good first step. Have a friend turn the steering wheel back and forth full travel as you perform the inspection. It is very helpful if you know exactly how to perform a comprehensive inspection of every single front end part, looking for abnormal wear and or play in that hardware. If you do not know how to do this type of inspection, pay an experienced professional to do it. Be sure to ask them if they are familiar with “death wobble”, as not all technicians are versed in this…..

Possible causes of death wobble are listed below. Isolating death wobble is a process of elimination; the root cause is not always obvious and it can often be caused by a combination of things! Always chase and resolve death wobble because if it is not resolved, it is such a violent event that it has the potential to seriously damage front end parts. From my personal experience, I would first concentrate on the track bar and the control arms and associated bushings.
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-Front tires out of balance (try swapping fronts to rear; see if symptoms change)
-Tire pressure. Don’t laugh. It’s not a root cause but can exaggerate the problem. Experiment with lower tire pressure to see if it helps
-Improper lug nut torque on wheels
-Front alignment out of spec
-Loose track bar
-Worn track bar bushings
-Worn track bar (check for play!!)
-Bad control arms and associated bushings
-Worn/damaged steering stabilizer (not generally a cause in and by itself)
-Worn/damaged shocks
-Worn/damaged tie rod end
-Bad U Joint
-Bad ball joint
-Loose frame mount
-Steering box loose
-Bad front hub assembly