Desperate to cure Death Wobble

I have owned the jeep for six months. I bought it in the bay area and drove it home with no problems. I took the truck out on 3-4 trails with no issues. Recently we made a trip up to Bald Mountain which resulted in a broken axle shaft and u-joint in the front axle. On the trail we removed the axle and drove home on the wheel bearing. We made it almost home (Kingsburg) safely.... and that is where a single pothole (on the front passenger side I believe) triggered DEATH WOBBLE.

This started several weeks of repairs in my spare time.

1-piece TJ style axle conversion (from vac disco setup)
new upper and lower ball joints
alignment (Done @ Gross and Stevens Visalia, stated dead on, no changes made)
Tires balanced
Newer used TJ wheel bearings
New trackbar bushings (Kevins Offroad Superdurometer Bushings)
New Durango Steering box
New Synergy Pitman Arm
Plated frame / unibody 1/4 plate both sides w/ 1 1/2 round stock welded between due to severe cracks found originating from steering box mounting holes.
All front suspension components have been checked at mounting points and bolts torqued to proper spec. Control arms are custom radius arms with a combination of johnny joints and bushings, all of which seem to be tight and in good condition.

I found visible play in the pitman arm when I had someone turn the wheels side to side. after removing the nut the pitman arm basically fell off. This was exciting to finally find a source of slop. After replacing the pitman arm The steering initially felt much better until the first test drive where it still had Death Wobble.

Steering setup is similar to Rusty's Offroad over the knuckle convension with heim joints and DOM tubing at the drag link and tie rod. The heim joints do not appear to have excessive play.

Because of the custom / homemade lift that was on the truck when I got it there has never been a steering stabilizer and this has never presented any issues. After researching and getting much advice on this death wobble I have purchased one and I am working on a mounting point. I view the stabilizer as a bandaide that will help regardless but I would like to track this down and find the root of the problem instead of masking it.

I have now mounted the stabilizer and it seems to help, but I would like to remove it and find the root of the problem.

I will be experimenting with different tire pressures to see if that makes a difference. I typically run 30-32 psi when fully aired up.

I have worked diligently through each possibility for the cause of this and I am reaching the end. I am puzzled by the truck driving down the road better than my lifted '99 wrangler for months, then one pothole later death wobble renders the truck useless.

I have heard of tire cords breaking loose inside the tire that can also be hidden when balanced that can initiate DW?

At any speed over 25 mph the smallest crack / bump in the road triggers a uncontrollable shake. This is not eliminated untill the truck nearly reaches a complete stop.

I feel like I have repaired, replaced, inspected, tightened, adjusted everything from the axle up and I am still having this problem. The trackbar mount seems solid on the frame side, but I am wondering if it is possible that the unibody has more severe hidden damage than I thought. When I removed the steering box and found cracks I was again happy to find a source of slop and to reinforce it properly. Can DW be caused by unibody / frame rails allowing slop?

I am truly at the end of my rope and next step is to find a shop that knows a thing or two that will help. Like anyone I am on a budget but I also want this to be fixed properly so that it is a reliable and fun vehicle.
Any and all advice / information is greatly welcomed.

1987 Comanche - 4.0
7.5" lift
35" tires
OX lockers front and rear

hasta

I've been through this so I totally get your frustration. Sounds like you have checked all the points that people say to check. You mentioned that you got your front end aligned. Is your caster properly adjusted? With 6.5" of lift and custom radius arms it could be pretty far from ideal. I believe I have mine set to about 6 or 7 degrees of castor with my 4.5" lift and Clayton long arms. I had death wobble until I corrected my castor angle.

You may also want to check the control arm bushings on the axle. The bolts may be tight but if the bushing is shot you'll still get death wobble.

Often, I have found that death wobble stems from a combination of small things rather than just one loose item. Id say that your theory is correct with the steering stabilizer being a band aid. I'm running heavy 35's with clayton long arms and heim steering and I don't have the least bit of a death wobble without a steering stabilizer. Good luck!

From the print out from the alignment I believe the caster is set around 8* which is more rather than less..it should be helping get rid of DW rather than causing it.

Control Arm bushings are in good shape.

I agree that it may be multiple things adding up to one big problem, but wouldnt some of the little things be more evident? Also do little things put it over the edge where it all of a sudden has extreme DW or would it be a slow process that gets worse?

Because it all started with one pothole I tend to think there is something I am overlooking. I no longer trust the truck while driving and I am basically just anticipating the DW at all times. Right now I can only limp it from here to there on back roads where I can pull over at any time.

If the frame is cracked where the upper trackbar mount is bolted could this be another cause? I only ask because it is an area that I have looked but it is not easily visible if thee is damage there. The bolts holding on the trackbar mount have all been checked and are tight.

I'm curious to see how this goes for you. I have an xj but I have been in the same battle with DW for quite some time and it feels almost like being taunted, hunting for something I don't see. Also on a college budget I can't just throw money at it.

You can try having someone pushing the front side to side while you put hands on every thing to feel for play. And have them rotate the steering wheel side to side.

Yes, busted tires can cause DW. Have you tried different tires? Rotated the front tires to the back?

That's where I'd start.

I'd also put an angle gauge on the ball joint to verify the castor angle.

In every case of DW I've dealt with the problem has either been shot CA bushings, track bar bushing, bad tires, castor angle or a combination of all of the above.

pics of the steering setup? is the trackbar frame side mount solid, welded and bolted? whats caster set at? what is toe? Pics of tires? crap worn out swampers will do it in a heart beat. New front tires might be your fix dude. track bar bolts loose. are you 10)%S sure you heims are good?
drag link and track bar are parallel and close to equal length? any frame cracks and fatigue around the track bar frame side bracket will cause DW potential and other issues. which tires and how much wear?


try another set of tires.

Did you put the stub back in the wheel bearing? Not having that piece in there lets the bearing separate and can cause a wobble