DW :-\

Gents,

I started with a stock XJ with 208k that suffered DW.

The first real step I took to address it was to purchase 5 new wheels and 5 new firestone tires and alignment. Problem not solved.

Next I installed an RE 3.5" lift with new leaf spring packs and new sway bar bushings at around 230k and alignment. Problem not solved.

Next I replaced all 4 ball joints, motor mounts, and alignment. Problem still not solved.

Now with around 240k on the click the only things not yet replaced on the front end are the bearings, TRE's, UCA's, and steering gear. What's the most likely culprit at this point?

the usual suspects are the track bar being lose at either end or the upper control arm bushings being worn out on the axle side. make sure the bolts on the steering box are tight and the bolts holding the frame side track bar mount to the body. also make sure the bolt that attaches the track bar to the axle is good and tight.

Have you taken it to a mechanic or looked for worn parts? No sense just replacing it all. Well, maybe. Your wallet

I am the mechanic.

The UCA's have been on my mind. I wasn't so sure they mattered that much for DW but I guess I was wrong. With 240k on the clock I'm sure pretty much everything is worn out.

Is it truly death wobble or a vibration? Could check the front driveshaft and see if its out of balance

I'd put each front wheel up, grip at 3&9 then at 12&6 and check for looseness , steering links and wheel bearings.
Drop the axle side of the track bar and inspect the bushing as well as through bolt's hole in the bracket for wear. Also, check the frame side joint and make sure the jam nut is tight.
I'd pull the Ucas and inspect, too.
With 240k, it could be anything between the unibody and tires.

I did try to move the wheels around and found a LOT of play in the ball joints, which is why I replaced them recently. It really rides and handles noticeably better but despite the high hopes, the DW is still present.

No noticeable play in the steering linkages, although it looks like there might be some at the output end of the steering gear. It's not a lot .. you don't really notice it while driving for example, but maybe any play at all there is a dealbreaker?

like, the shaft support bearing is loose? Yeah, I think that would do it. I mean, a dead spot in the steering - like, excess lash in the steering gear - won't cause death wobble.
If you are saying you can grab & shake the output shaft that the pitman arm attaches to... replace the box for $100 with a Lares unit from rockauto.com

Confused ... will it the play cause it or not?

If the box simply needs a slight backlash adjustment (you know that nut on the top of the box) then typically no that will not cause death wobble, at least not that Ive seen. However If the sector shaft has a ton of side to side play that could be a factor. Though id still bet there is another true cause of it.

so is it a vibration that won't go away? or is it the holy crap i'm gonna die whole rig shaking like a leaf until you stop type thing?

TRE's, UCA's, worn steering box, suspension out of alignment will all cause DW (and I'm only listing the stuff you haven't replaced) ... it's rarely just one thing, but a couple issues that contribute to each other.

You mention all these alignments. What's the caster angle set at?

You mentioned UCA's. I assume you replaced the LCA bushings when you installed the lift?

Every case of DW I've dealt with was either the trackbar, caster angle or LCA bushings.

Lowrange2 said:

Every case of DW I've dealt with was either the trackbar, caster angle or LCA bushings.

Click to expand...

same here, but with upper bushings wearing out and letting the top of the axle pivot forward and back.

It's definitely real death wobble. Hitting certain types of bumps starts the DW and the only way to stop it is to slow down to below around 40 mph.

The LCA's were replaced as part of the lift.

Most recent alignment shows total toe of +0.02 degrees and camber of 6.0 and 5.7 degrees left and right respectively.

And, thanks for the advice! TRE, UCA, steering gear are, like Devilfrog mentioned, pretty much the only parts that haven't been replaced. They are what I'll be looking at next .. probably starting with UCA's.

But I wanted to ask first to make sure I wasn't overlooking something obvious.

Caster. What's your caster?

EdIt: ^^^^
whats your caster?

more than likely your trackbar bracket at the frame is loose. you cannot know for sure without putting a 2 ft breaker bar on the thing and crank on all 4 bolts real good. next is the hiem at the frame side, and that bolt, and next put a breaker bar on your track bar bolt at the axle side and crank on it. also make sure your steering box bolts are tight and make sure you dont have any frame cracks around the box and trackbar.

ive done this so many times for so many XJ locally its almost rediculous. they bring their rig over, I ask them if they tightened track bar bolts and checked all trackbar joints/bushings. when I get under there to look while they turn the wheel back and forth I always see: A. bad trackbar bushing or joint at one or both ends AND/OR B : track bar frame side mount moving (you cant know until you put a big ol breaker bar on it) AND/OR C: loose axle side bolt (you cannot know until you put a big breaker bar on it if its loose or not) AND/OR D: loose frame side trackbar bolt(not the 4 mount bolts, the bolt that holds the trackbar to the mount)

ive seen guys throw tons of money at DW and then I walk over with a 1/2" drive 18mm on a breaker bar and fix it 30 seconds. Not always that easy. Ive seen it be frame cracking too. Never hurts to plate the frame up front .

Other things that probably wont cause DW (other than really really bad tires) :

ive driven on totally shot ball joints(with a loose high steer arm that moved ) : It wanders. no real DW. scary wondering though. like changing lanes while driving straight sorta thing. bad hub bearings and worn spindles made it worse.

bad stabilizer: steering it not as tight. seems to wander a little more than normal, but thats probably because your TREs are shot.

out of balance / Bad tires: will get you DW sometimes, or vibes, or both. I had some old crappy swampers that did this. New tires fixed it. they couldnt balance, bad uneven wear. . get them balanced first before replacing. ( i personally dont balance my 36 iroks and dont have vibes or DW)

cracked frame: lots of popping and creaking/sometimes even get DW - weld it up and plate it.

blondejoncherokee said:

EdIt: ^^^^
whats your caster?

Click to expand...

?

Lowrange2:

"Most recent alignment shows total toe of +0.02 degrees and camber of 6.0 and 5.7 degrees left and right respectively."

Sorry! Meant caster, not camber! That would be a ridiculous amount of camber too!

mdmbkr said:

Lowrange2:

"Most recent alignment shows total toe of +0.02 degrees and camber of 6.0 and 5.7 degrees left and right respectively."

Sorry! Meant caster, not camber! That would be a ridiculous amount of camber too!

Click to expand...

lol, That's what I thought you meant.

I was going to suggest that your axle was bent...

I don't know what +.02 degrees of toe equals but I run about 1/8" toe in. I run about 7 degrees of caster.