apac020

Hi guys, I'd appreciate some help here. I've read almost every death wobble thread out there so I think I understand the problem pretty well. However, I can't seem to rid myself of it. Some history:

3 years ago- bought my 95 xj, test drove fine, put some rollers on it because I didn't want to buy the POs tires. Had death wobble issues when hitting bumps at ~50-60 mph. Came with a 3" Rough Country lift.

2 years 9 months ago- changed tires and cut fenders. Installed 33x10.5 KM2s. No more death wobble, but a noticeable shimmy around 55 MPH. Had the new tires balanced a million times and finally roadforce balanced. Got the shimmy to be almost unnoticeable with one specific tire configuration (it came back if the rear tires were in front) up to about 65 MPH. I just drove under 65 mph without issue for a while.

See this thread for efforts to balance tires
https://www.cherokeeforum.com/f59/th...me-off-156959/

2 years ago- Increased lift to ~4" in the front, ~5" in the rear. Installed IRO Double Shear track bar. I still have stock UCAs and the non-adjustable Rough Country LCAs from this kit http://www.roughcountry.com/jeep-sus...-kit-670x.html.

1 year ago- Installed Serious 1Ton UTK steering. Shimmy that I've had at ~65 went away completely. I have run without a steering stabilizer since this time.

2 months ago- Started noticing some shimmying when hitting bumps on the highway driving back from Moab. A couple weeks later, got death wobble at ~40 MPH hitting a bump on an entrance ramp. Noticed my TRE castle nut had broken free and the TRE was loose in the knuckle. Tightened it up. 1 day later, death wobble again. Noticed that it seems to be a lot workse when I'm turning left (I'm not an ambi-turner!!), decide to replace my wheel bearings, ball joints, and upgrade axle shaft u-joints to 760x.

Today- Finally got time to install the ball joints, wheel bearings, and u-joints in the last couple weeks. The u-joints felt ok, but I found 1 bad wheel bearing and both lower ball joints were shot. Was really optimistic that this was the fix. I also rotated my tires. Finally highway tested it today, and it's a mixed bag.

Good news: The front end and steering response feels much tighter.
Bad news: I definitely felt a shimmy in a couple situations. 1) Was going around a corner at about 40 MPH and hit a bump. It didn't death wobble, but there was a very noticeable shimmy for about 1-2 seconds. The front end being tighter probably kept it from DWing like it did a couple months ago. 2) Any time I was at about 55 MPH it started to shimmy. Not death wobble, but that familiar, white knuckle feeling when you feel just a little resonance.

My instincts tell me that the shimmy at 55mph could be tire related, but that wouldn't explain the shimmy hitting bumps at 40 MPH.

In this time I've put about 6000 miles on the jeep. This is my project/expedition/home depot vehicle, so it doesn't get driven a lot.

So, just to summarize, these are the fixes I've addressed
Replaced track bar (IRO double shear)
Replaced steering (Serious Steering 1Ton tie rod and drag link)
New ball joints
New wheel bearings
New axle shaft U-joints
Upgraded steering box brace
Checked steering box bolt torque
Lug nuts torqued
Inspected control arm bushings - they look OK

These are the things I can come up with that I haven't addressed
Adjustable LCA/UCAs - I'm not sure what my caster angle is, but it's whatever the fixed LCAs and stock UCAs provide at 4" of lift. My axle looks relatively flat, but I haven't taken an angle measurement.
Front driveshaft balance
Replace shocks
Add a steering stabilizer - everything I've read says I should NOT need one of these, that they just mask other issues. Would it reduce the bump steer?
Tire balance - I swear these tires are impossible to balance. I brought them back to discount a million times and they always say they are balanced, but the shimmy is always there at 55 mph. Should I try balance beads?
New tires - These tires were $1000 and have only 6000 miles on them, I'd rather not get new ones

Of my remaining options, what should I try first? Any other suggestions?

Thanks in advance for all of the help/moral support .

Tsaani97xj

"Inspected control arm bushings - they look OK "

This stands out to me. Change them just because.

Id seriously get the alignment checked so you know what your caster is. Im betting this is where you'll find your gremlin.

I hate vibes. Chasing my own.

Gluck.

apac020

Thanks for the suggestion. Control arms are probably the next likely candidate, but they are also expensive to replace .

Just checked my caster using a magnetic angle finder, it's about +9 degrees, give or take. So a little over spec, but from what I can tell, over spec is really not an issue for DW.

94HOCHEROKEE

I really doubt all this is from a bad balance but if you think its worth a shot, try road force balancing... are your rims bent? You've almost replaced the entire front end!!!

apac020

OK just took off the front driveshaft and took it for a spin. Still had the same shimmy at 50-55 MPH. Cross that one off the list, too.

Actually, the more I think I thought about it the more I think the shimmy is from rotating my tires. This feels very similar to what I had when I first got them, and finally found that configuration that worked. I'm going to try rotating them back in the morning and see what happens. These tires really have been awful.

I wish I knew someone with 33s so we could swap for a day.

I already had them road force balanced a couple years ago. They checked for bent rims, too, and I had to warranty one that was.

Most of this recent "actual" death wobble was from work steering components, I believe. I think the steering is so tight now with new stuff that I'm noticing the shimmy problems. The slop probably consumed them before.

94HOCHEROKEE

I think you might be on to something now.... with all those new parts just be glad its not full blown death wobble. Good luck man!

94HOCHEROKEE

What kind of tires are you running? 33x12.5?

94HOCHEROKEE

Nvrmnd. I read further up....

BenS

Your caster being that far positive would actually help you. That is about where mine is at right now. You might still want to grab an adjustable upper anyways though since you are putting some stress on your front end with that caster. My money would either be on tire balance or track bar. Did you check and make 100% sure that the bolt on the axle bracket was a perfect fit? I've also seen a few where the bracket on the body for the double shear track bar was installed incorrectly.

BenS

Also which serious utk kit did you get? inserts or reamer req'd? Have you checked your tie rod ends to see how much play they have now?

Rockfrog

Check toe-in ... I eliminated a good amount of DW episodes adjusting it. Currently sitting at 1/16" of toe. Adjustable uppers or lowers would help with caster adjustment as that will have an effect as well. At 4-5" you want to be in the 5 degree range. 7 degrees just ain't gonna happen as the driveshaft angles become issues.
Before I went to a long arm suspension, I had eliminated all components (by check and/or replacemnet) And eventually found the last culprit was bracket flex. My custom frame side Trac bar was flexing but only under force. A simple driveway check looked normal. On the road the bracket was twisting around the bushing and the brace. A bit more gusset in and boxing cured that.
Alignment cured the bulk of my issues, FYI 3/8" toe in is bad.

andrewmp6

Is your steering link and trackbar at the same angle?

apac020

Update

It's the tires. I rotated the 'good' ones back to the front, and no more steering wheel shimmy. I do still feel a shimmy, but in my 5-speed shifter. My conclusion: one or both of my rear tires are out of balance, or out of round. The shimmy on rear axle would transfer directly to the driveline when in the rear. Everything in the front feels very tight.

I'm going to swing down to discount today and see if I can get the balance fixed, or at least check for a defective tire. Might just have to eat the cost and ditch the bad ones.

Codenamefa

Have them balance all of them and check to see if any of the rims are warped. I had on my old steelies years ago get warped when I was out playing a little rough and I didn't find it until I decided to get new tires and the guy showed me and the wheel was slightly warped and was causing all the problems.

ZJMAX

Just a question but are your rims hub centric or lug centric? If hub centric and the hub is smaller than the hole in the rim you may need to get some centric rings. Had many people do this and fixed their vibration they have been trying to track down for a long time.

Max