Death Wobble, help please!

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

since your steering is otk is your track bar otk and parallel with the drag link? did you rotate tires or borrow someone else's (could be shifted belts or bent rims)? bolts for the heims tightened to spec and no slop in the holes through the knuckles? check for cracks behind track bar mount. take stabilizer off because it could eventually make you think you fixed it but havent cause its a band aid....

I'd be curious to see the spec's that the alignment shop was comparing to and see how they stack against what the "old guys" here recommend. A stock Cherokee may have different alignment needs than one with a 7.5" lift and non-stock control arms, etc - right?
I have two other thoughts:
First - lose 2- 2.5" of lift height and see how it's going. At 7.5" lift, you are pushing things. More lift, harder to keep things well behaved.
Second - and I hate to say this - it's probably something you've already checked but green-lighted. When guys get this far down the list it's usually because they missed something in one of the parts on that list.

Also, it might help to see pics of the front suspension.

Trackbar and drag link are very close to parallel. I have rotated and re balanced tires. All steering linkage has been torqued and no slop visible.

I agree that the stabilizer is coming off at least till I fix this problem.

I will search for the specs from the alignment shop so that others can compare. Loosing some lift is not a bad idea that I'll have to consider.

I agree it is something I have "checked" because at this point I feel I have been so thorough I must have missed something.

Some pictures(better lighter ones to come)

My first stop would be to remove the bolt on the passenger's side that connects the steering to the knuckle. Check for any sign of movement, any slop in the way the bolt fits the knuckle, any ovaling in the knuckle, etc, as well as the starting torque of the bolt. I don't know if it's 5/8 or 3/4 but either way, if it is torqued correctly, it's more than 200 ft lbs- or damn-near-hernia tight.
This is my first stop because, if I'm seeing the picture correctly, the top link is vertically a good 3" or more from the knuckle, which is a pretty demanding situation for that bolt. Any problems in that area at all could create death wobble - and you could have created just such a problem while 'wheeling.
You could move the tie rod under the knuckle and keep the drag link over it, might help reliability, but maybe a more crawling oriented voice will chime in here.

I have checked the bolt and I understand the stress on it. In the process of finding the cure I have already flipped the tierod under the knuckle. It changed the geometry of the linkage slightly but still very close to parallel to the trackbar.

I will go back and double check the torque and shape of holes in the knuckle.

I like to use easily replaceable parts but I had an idea for the bolts on the steering knuckle. Is it possible to find a wheel stud long enough with the correct diameter that I can press into the hole in the knuckle / pitman arm. Has anyone seen this before or thoughts?

From the pictures, I can see that your drag link and track bar are nowhere near parallel. The frame end of the track bar is the same height as the pitman arm end of the drag link. And the other joint of the track bar is lower than the other joint of the drag link. Joint to joint is how they should be parallel, not just the tubing itself...
Also, I'd replace the axle U-joints with new and the unit bearings. I've found what seems to be little to no play I either component can cause too much microplay that contributes to the snowballing effect that becomes DW...

i got a 95 jeep grand Cherokee, and i have the death wobble going on. it comes when i hit 35mph. i change the tie rods and the track bar, check for play, found it in the sway bar, change the bushing. but still have the death wobble going on? could it be my tires and/or a better alignment? just found out the jeep had been in a accident. also my passager side tire sticks out, while my driver side come in to where my sway bar link extension is rubbing the coil spring. i need help!!

delas23 said:

i got a 95 jeep grand Cherokee, and i have the death wobble going on. it comes when i hit 35mph. i change the tie rods and the track bar, check for play, found it in the sway bar, change the bushing. but still have the death wobble going on? could it be my tires and/or a better alignment? just found out the jeep had been in a accident. also my passager side tire sticks out, while my driver side come in to where my sway bar link extension is rubbing the coil spring. i need help!!

Click to expand...

You need to do an alignment for sure to start with and get your tires balanced. That in my opinion should be the baseline for trying to solve DW. The alignment can be a diy job if you have a little time. Gojeep has a good writeup on his website. However if the jeep has been in an accident have it inspected by a reputable shop in relation to the frame/alignment/drivetrain.

Any other specs on the suspension? Type of lift control arms and tracbar make and model? Size tires?

make sure track bar and drag link are parallel. in the pic they don't look parallel. do what you have to do to get it there. put a breaker bar on the frame side bolts for the mount and crank on them.

Set caster to say 6* and get toe dialed in. Make sure tires are not fubar.

make sure heims are all good. ball joints and bearings too. And check all bushings.
tighten everything up good.

try running 25 PSI on the street.

Is the steering box good? are the steering box to frame bolts tight? any broken ears on the steering box?
are you shocks any good?