Possible Death wobble

[McClare]

92 MJ, 3" skyjacker shocks, coils, new leaf pack, new LCA's.

 

When I first lifted it I went into a death wobble and then I got an alignment and that seems to have fixed it until the other day. It didn't go into the wobble, but once in a while when I hit a hard bump at high speed I can feel the wheels shake back and forth a sec. A little harder hit and I'd be done.

 

My question is what should I do about it? Would a dropped pitman arm help? I've seen people put 1" drop pitman arms from a ZJ on and I'm curious if that solved the problem. This is a daily driver.

 

Cheers

thanks

[JeepcoMJ]

no drop pitman arm. by installing that, you disrupt the parallel that the drag link has with the trackbar and that will screw the geometry of your front axle up, giving you bump steer.

 

I think you probably have a lose trackbar, OR a bad axleshaft ujoint (or two). my ujoints are bad on the front of my truck and were binding (uh...I say were because I'm pretty sure tha they're no longer 100% intact...it's getting fixed this week) and when that happened while hitting a bump, they wobbled the $#!& outta the front end.

[Rob S]

92 MJ, 3" skyjacker shocks, coils, new leaf pack, new LCA's.

 

When I first lifted it I went into a death wobble and then I got an alignment and that seems to have fixed it until the other day. It didn't go into the wobble, but once in a while when I hit a hard bump at high speed I can feel the wheels shake back and forth a sec. A little harder hit and I'd be done.

 

My question is what should I do about it? Would a dropped pitman arm help? I've seen people put 1" drop pitman arms from a ZJ on and I'm curious if that solved the problem. This is a daily driver.

 

Cheers

thanks

 

A ZJ pitman arm will drop the steering down 1", and yes it does help keep the angles closer to stock. I will use one on my MJ.

DW can come from a many things, usually track it to some steering/suspension component that is worn or loose. Check the trackbar and LCA'a, make sure they are tight. Then go over the rest of the steering, tie rods, etc. I have heard that an out of balance tire will cause it too, may try rotateing the tires, see if that helps. So many things to check, just try and eliminate them one at a time.

:cheers:

[Duner]

The drop pitman made the biggest difference in my truck of just about anything done. You have to get the track bar as close to parallel with the steering linkage (knowledge I could of used before I started lifting the MJ) to help eliminate the bump steer. As for everyones personal experience with this it will depend upon the different componets they chose to use. Every mfg has different mounting ideas especially when it comes to track bars. If you got one that mounts closer to parallel with the linkage you may not need the drop pitman. My skyjacker track bar definitely needs the pitman dropped.

 

Eagle it may be about time to have everyone gather up all of there lifting knowledge and make a "sticky" for the sight. We have all been down the budget road and many of us are now in the high dollar areas and we have learned a lot along the way. I'm now the jeep lifting expert at my school. I know everyone's opinion is different about the mfg's products but I think that there is still some basic knowledge that is true of all the Comanche/Cherokee lifting geometry that we could compile into a sticky for all of the newbies and help remind all of us oldies of all the things we forgot along the way.

[500 MJ]

Trackbar has ALWAYS been my culprit...

[McClare]

If I took a few pics of the steering you think that might help diagnose the problem?

[Pete M]

If you haven't done it already, I recommend having someone wiggle the steering wheel back and forth while you watch for slop in all the various joints, including balljoints, TREs, trackbar etc. For the balljoints you'll also want to jack up the tire and push-pull on the top and bottom of the tire to see if it moves. Also check the condition of the bushings in yout UCAs.

[Renegade]

As far as a drop pitman arm, if you didn't install a drop bracket for the track bar on the frame end, you shouldn't need a drop pitman arm. No matter how much lift you run, the original parallelism should stay close to the same, no matter the angle.

[McClare]

actually come to think of it, the track bar did come with a drop bracket. I think it was an inch or two. Maybe that's the issue

[jared]

As far as a drop pitman arm, if you didn't install a drop bracket for the track bar on the frame end, you shouldn't need a drop pitman arm. No matter how much lift you run, the original parallelism should stay close to the same, no matter the angle.

 

but that is part of the problem. with the stock trackbar tie rod end it will wear significantly faster due to it always being at an extreme angle.

 

but i do agree that if you drop the pitman arm, you need to drop the trackbar the same amount to avoid steering problems.

 

but the treack bar and drag link not being parralle would not cause DW to my knowledge

[jared]

and i do not like the rustys HD drop trackbar bracket. i think the bracket flexes do to the weak unibody frame.

 

i had it on my xj and i didn't have a frame steering box stiffener either. i got deathwobble afterewards of installing it (i think because the bracket and frame would twist under the force of the 33s). and i did not have it before. and all the bushings were new.

[McClare]

So where do you get the drop pitman arm? Is it the stock pitman arm for the ZJ and it drops the MJ by 1" or is it actually a 1" drop for a ZJ?

[jared]

any suspension company has them, but the zj one might be a 1'' drop compared to a mj. idk

[Eagle]

Trackbar has ALWAYS been my culprit...

Yeah, and tire balance has always been my culprit (except in the WJ, where it was warped rotors), and for someone else it's insufficient caster...

 

There is, unfortunately, no one thing that anyone can point to and say that THIS is the definitive cause of death wobble.

[JeepcoMJ]

Trackbar has ALWAYS been my culprit...

Yeah, and tire balance has always been my culprit (except in the WJ, where it was warped rotors), and for someone else it's insufficient caster...

 

There is, unfortunately, no one thing that anyone can point to and say that THIS is the definitive cause of death wobble.

 

we can say THESE are the definitive causes of death wobble.

 

now figure out which one you have dammit :eek:

 

j/k lol

[Oizarod115]

well, i have DW and its not tire balance, or track-bar... or lift issues.

its not brake rotors, its not ball joints, its not wheel bearings...

 

;) there's way to many things that can cause DW, old/rotted bushings are likely the origin of my problems.

[Pete M]

Yup, just about anything in the front suspension/steering that moves or flexes could be a cause or it could be a combination of several slightly worn items.