New cherokee owner experiencing what I think is the dreaded death wobble. A little background, I recently purchased a 96 cherokee with around a 3-3.5" lift. Appears to be coils with a small spacer on top and full leafs. Stock lcas and pitman arm and stock trac bar. Background, I am not new to jeeps, just Cherokees. I've dealt with death wobble on my 2013 JKU

The problem; anything below 50 mph, the thing drives as I would expect it to. Once I get over 55 if I hit a bump and the violent shaking begins (severe shaking with a feeling of impending doom) until I get down to 50 or less. Highway speeds are nearly impossible. The only thing I can see that may be worn out is the drag link end attached to the pitman arm. Everything else appears to be okay with no play while my friend turned the wheel back and forth.

I've done some searching, just looking for some input.

 

You need new lca so you can adjust your castor.

 

Yup classic " death wobble" track bar is a good place to start,but it could be anything ,even if the part passes the push pull,pry test.

 

Start with the trac bar. Don't even bother to look at it. Just get a new one, you need it anyway, and there's a good chance it will fix your problem.

 

Im not disagreeing with you if its stock he needs a new one but when I did my lift I put on the best TB to stop DW I got it anyway. I then installed some adjustable LCAs and set my castor correctly and boom fixed it.

 

Also take a good close look at your ball joints. A lift also meens bigger tires ,add a couple hundred thousand miles and they might be getting alittel loose and worn .

 

x2, caster will make your tires dance! Not enough will net you a lack of return to center and dw.

 

Lcas would be the next thing I recommend. If he wants to do them both at the same time that'd be even better.

 

I'd get replacement LCA's, replace a few tie rod ends, maybe the track bar, then go get a pro alignment.

 

I have dealt with and fixed DW from hell - 89 MJ 3 inch lift 225/75R16s & Learned a bit - - - Go after easy 1st - Rotate tires F to B - DW going away just by slowing down & not stopping is classic tire imbalance - Ck the toe - Hard telling if the PO had it adjusted after the lift - needs to be zero to 1/16 in - - Gotta know the amount of lift for the correct control arms length - Too much + r - caster alone will not cause DW but will amplify probs caused by other worn components - U&L control arm bushings, BJs, TREs, TB & TB angle(should be parallel to drag bar) everything else including the steering box - - Thrust angle is another can of worms - pretty much gotta be zero in order to avoid mega frustration setting the toe - Common causes of TA probs on XJ/MJs are a wreck, big dif in worn control arm bushings on one side only & LCA shims missing/mucked with or incorrect TB - All will cause axles to not be parallel - - - - Most shops, like 99% of 'em, will not have alignment specs for a lifted XJ & if they say they do they're still gonna go by the amount of lift you say your jeep has, right wrong or indif - Also, factory recommend for XJ/MJ lifts was "DO NOT" - These guys do alignments everday & know how to dodge probs with non stock/oem vehicles - Typical is "sure, no problema", get the money upfront, set to factory specs regardless because of the liability lawyer/law suit thing & then start spreading the BS when things go south - - - - - - Do the alignment yourself -- Isn't hard - a helper makes for easier but not necessary - - - Here's some links - - DWs been beat to death on CC & NAXJA - lotsa good info both places - -

http://comancheclub.com/topic/37076-...nt-after-lift/
scroll down for pic/diagram

http://www.naxja.org/forum/showthread.php?t=41349
how to find amount of lift

http://comancheclub.com/topic/28215-...th#entry289657
control arm chart - scroll down

http://www.jeepfan.com/tech/jeep-wrangler-jk-alignment/
info on TA & TB

 

Confused about what I have read about getting longer lower control arms, or adding shims, to bring the Caster back to a lesser amount to lessen Death Wobble over 55 MPH. My Jeep is a 1988 Cherokee Lorado L6 engine A4 trans. Was getting DW mildly at around 60MPH freeway, could feel it coming on and reduced speed to stop it. I replaced all 8 control arm bushings with Moog units from NAPA Auto parts. While I had the front end apart I installed a 2" Energy Suspension spring spacer lift kit. My shocks are about 50% "new", track bar appears to be tight, steering damper replaced, tie rod ends, ball joints feel OK. I am running 6 year dated BF Goodrich TA 235/75/15 M&S tires. Now this morning the DW comes back without any warning signs and at 55 to 65 mph it wants to rip the front axle out from under the Jeep. I took it into a tire shop and when we test drove it the tech about crapped in his shorts when the DW kicked in, said he had never seen a Jeep that bad. They re-tightend some of the control arm bolts, set the toe in, then said that the Caster was 9 degrees, should be closer to under 6 degrees. Apparently they did not adjust the Caster. (Toe in was reset to 0.04 inches, Caster was left at 8.8 left side, 8.9 right side.) Here is my pressing confusing question,, IF I have too much positive Caster, should I be pulling the bottom of the front axle assembly to the rear of the jeep to take out some of the excessive Caster, by shortening the dimension of the frame attach point to the axle housing attach point?? That is, removing the shim material from the mount where the rear of the lower control arms attach to the frame to allow the control arms to move to the rear? There is a slotted area where the bolt that attaches the rear of the lower control arm bushing to the frame sits, the adjuster is full forward, there is a thick shim between the rear of the adjuster plate and the rear of the control arm mounting box on the frame. This is pushing the control arm foward causing increased Caster angle. What am I missing out on here or was the tire shop missing something about changing the Caster by not REMOVING shims as needed to shorten the lower control arm dimensions to pull the caster back more vertical?? Thanks, John

 

This should answer your question.....

 

Your chart confuses me this is positive castor.

Airjohn positive caster will make the vehicle more stable at high speeds. Think about motorcycles. They are built to go fast and have a lot of positive castor. If positive castor made it less stable they would be hard as hell to drive at speed.

 

You have 3 degrees to much positive caster should be around 6 for high pinion....9 degrees is for high pinion...

 

This link will be a good starting point. For angles....http://go.jeep-xj.info/HowtoAlignment.htm