Yet another death wobble help request

[blakews2217]

So I’ve been in and out of the front end of this thing for months. It’s a 2000 xj classic aw4 with a 241 I believe also with a 2 inch lift and shocks.
Shortly after the lift was done I was developing death wobble slowly. I ordered and installed a track bar first. No difference. Next I ordered LCA and UCA bushings. Couldn’t do the top ones due to lack of time but the lowers made a world of difference. I went from being banished to under 40 to being able to chance runs to 50 or 60. Still not right though. I was due for tires so I put on some 265/75/r16 handcook dynapro ATMs. I also did the UCA bushings and all the TREs today. Eyeball and tape measure aligned it. Still a violent wobble. Bad enough to almost make me lose control. The track bar and drag link are parallel atleast to what I can see. Now I sit in my house frustrated I’ve dumped so much money into the front end. I’m reaching the end of my patience quickly and have run out of ideas. Any help would be appreciated.


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[smokeyyank]

Just a thought, I cracked my unibody at the steering box and it's what caused my issues. Also suggest going back through every bolt and making sure it's tight. Out of curiosity what track bar did you put in?

[lawagoneer]

Another common place to loom is the axle end track bar mount. The bolt hole will enlarge and can cause hard to diagnose death wobble

[RCP Phx]

Yes a couple notes here. What trackbar did you buy? And get real alignment numbers first! The angles only effect the bumpsteer.

[techno1154]

And ball joints???

I had the same problem as you do. I replaced, tightened, checked and re-checked everything on the front end and nothing helped. The I removed the steering knuckle and found the ball joints were bad,....especially the lowers. They showed no up and down movement when everything is installed. Dismantled, they had plenty of side to side movement. My highway speed have moved from 40 MPH to upward of 80 MPH after they were replaced.

Proper balancing of the tires and alignment are crucial.

[themauler]

Before you buy any more parts get the castor right and the front axle toe in correct. I have been there clueless holding out to get an alignment. Decided to take it to the shop, got it back a whole new animal.

How many miles are on the front axle components?

[blakews2217]

Originally Posted by smokeyyank

Just a thought, I cracked my unibody at the steering box and it's what caused my issues. Also suggest going back through every bolt and making sure it's tight. Out of curiosity what track bar did you put in?

When I swapped my steering box ( that was a whole other issue) I looked around and didn’t see anything but that was about 9 months ago. The track bar I got was the OE type from rock auto. I’ll go get it aligned after payday. Should I put the ball joints in before that? Is there a castor adjustment? I only saw the toe adjustment. Also, the tire shop I had mount and balance my tires said that the tires didn’t balance too well. I just wanna say thanks to everyone who responded.


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[blakews2217]

Originally Posted by themauler

Before you buy any more parts get the castor right and the front axle toe in correct. I have been there clueless holding out to get an alignment. Decided to take it to the shop, got it back a whole new animal.

How many miles are on the front axle components?

Depends on what parts? I replaced every suspension part between the axle and the body except the springs and all the steering linkage as well. I did notice some play on the input side of the steering box but I find it hard to believe that would do it. The oldest part that is routinely changed is the driver side u joint and both wheel bearings.


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[RCP Phx]

Well stock trackbars are junk! That also means your axle is not centered unless something been done you haven't told us about Again, check the mounts on both ends for "wallowed" out holes and loose bolts. Check all the tre's and check the ball joints. The list goes on and on for DW!
Caster can only be changed by adj arms or adj/offset ball joints but not likely your problem since you increased the caster vs running to little.
Camber can only be changed with adj/offset ball joints but again not a likely cause.

[ehall]

anything on the front end is suspect. Broken steering brace, ball joints, two things you haven't replaced that are probable.

Its not wasted money, you're resetting the maintenance clock on all this stuff, probably needed doing anyway

[Green XJ Jeep]

I have had worn brake pad sliders on the knuckle causing the pads to hang up causing death wobble.
A sticky caliper will as well.
Lots of potential causes you just need to keep picking away at it

[RCP Phx]

Originally Posted by ehall

anything on the front end is suspect.

Well said! I also didn't see any mention of the "drag-link"?

[blakews2217]

The drag link is parallel to the track bar. As for the cause I believe I’ve found it. First of all don’t trust your previous work. I found the frame side of the track bar was 1/3 turn loose. Got it tightened and kept lookin. I found the frame is cracked right under the steering box and up the side. This is a perfect excuse for a winch bumper. Thanks everyone. I tack welded the bit I could reach with a fuzz box but still needs supported. I found this with a buddy cranking on the wheel while I was looking. I saw what looked like the steering box and the frame separated only while cranked to the passenger side.


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[ehall]

There ya go, that crack will make a ton of vibration at the magic frequency

[blakews2217]

Originally Posted by ehall

There ya go, that crack will make a ton of vibration at the magic frequency

It’s not big but with it being unibody I can see that doing all set up work for dw to go to town. I girl I’ll swap my exauest headset at the same time I weld that up. Ontop if the weld I’m going to build a better brace and a backing plate on the other side of the frame. Basically making a frame sandwich. I’ll post pics as it comes along. It’s easy when you have access to a full machine shop with cutting torch and welder along with mills and lathes and plenty of hand tools. Also, no sway bar so I can incorporate that and build a bolt on brace. Maybe make a basic stiffener that runs both sides?


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