DEATH WOBBLE..? 88 pioneer

[81Chero]

Never had it before on road vehicle (1-tractor did) but had son with me coming from a salvage yard and don't know what really started it but alarmed me and scared the ____ out of him..

 

Only did it once since I've had it but nonetheless. When I got it i did the wheel tug on it but that was sitting for a while and didn't feel all that bad.

Going after church today to look under it and see what's up.

 

Also, if I'm going to be replacing stuff, Are there any brake upgrades for the MJ's?

(maybe I should start another thread)

 

E

[Keyav8r]

Brake upgrades - 96 XJ dual diaphragm brake booster and master cylinder. Check DIY for that and I believe I saw something on upgrade to WJ calipers and rotors. Didn't think to pin it.

There are several threads on death wobble causes and remedies.

[Eagle]

Start a separate thread for the brakes -- death wobble is going to occupy pages and pages by itself.

 

Everyone has their own pet theory as to what causes death wobble and how to cure it. My personal pet theory is that it's usually caused by out-of-balance tires.

[Incommando]

Check your track bar. On the body side mount the hole can become wobbled out and cause it. If you haven't recently changed the suspension or tires this is a good place to at least check. Heck it is a good thing for any of us to check.

 

(The booster upgrade mentioned above is a great one)

[91Pioneer]

Brake parts are unrelated to death wobble. Tackle the critical DW first, then worry about spending money on brakes later. Track bar is a common problem but it can also be a bunch of other things.

[az comanches]

Do like Eagle said get your front tires balanced. My tire balance felt pretty good, had them rebalanced no more death wobble. The times I experienced it, it only happened at over fifty mph when hitting a pothole or depressions. Since the balancing no more DW. Easy fix. The right front seemed to be the one that made the big difference. I had put my spare on the right front, and had no DW. That's when I went for the balancing.

[Motorcharge]

Look for fresh steel with a flashlight. It will give you a good place to start because you'll know what's rubbing if that's a cause. If you don't see anything obvious from that go through literally everything in the steering and front suspension and torque and replace anything loose or worn. It's always something simple with DW, but it's just trial and error and tedious to fix. I'm dealing with it myself atm and hoping rebalancing my tires fixes it. Like others have said mine only happened at 45-50ish when I hit a manhole cover, pothole, ect in the road. They've got less than 3k on them, but I haven't balanced them since I bought them 3 years ago and they were pretty off when I checked them yesterday. There was one that felt weird even after I balanced it so that went on the rear. Ran out of shop time before I could bleed my brakes so I've got to wait til Monday to see if that solved it. If you narrow it down to tires find a shop that has a Hunter Road Force balancer and have them use that.

 

As for brakes, what's your issue with them? I wouldn't mess with the front brakes other than replacing worn parts but I'd do a disk swap in the rear or an axle swap with disk brakes such as an 8.8. They're a huge improvement in braking however you add them.

[Truckcom]

Don't forget to check the DPD {deathwobble prevention device}, otherwise known as the steering damper or stabilizer.  That's what it's there for.  Back in the day, a brand new Jeep would develop the shimmy if it was removed.  I don't see its importance mentioned very often in this forum.

[81Chero]

Don't forget to check the DPD {deathwobble prevention device}, otherwise known as the steering damper or stabilizer.  That's what it's there for.  Back in the day, a brand new Jeep would develop the shimmy if it was removed.  I don't see its importance mentioned very often in this forum.

Thanks sir, never thought of the steering stabilizer. That's probably the cleanest part (non-leaking) so I didn't think there was a problem.  All my jeeps have them but never had this issue. Is it something with the linkage geometry of the suspension? My M-715, 81 Cherokee, 92 Cherokee had them, Now this on such a lightweight doesn't make sense to me.

Never had it with my Chevy's in the past. 

 

The reason I seemed to switch to brakes was that it looked like the rotors were grooved some and that its' got over 230K on it, I just figured that Since it would be up in the air and getting things checked out. 

Another thing is that the steering box is supposed to be a variable box. This one turns about 1/8 before the tires do, so maybe the XJ box swap is needed NOW! And maybe the whole problem with the wobble.?

Remember, Ive just had it for a week or so and just a couple days "legal" so I'll be asking more as things go.

 

Thanks again guys.

E

[Motorcharge]

Don't forget to check the DPD {deathwobble prevention device}, otherwise known as the steering damper or stabilizer.  That's what it's there for.  Back in the day, a brand new Jeep would develop the shimmy if it was removed.  I don't see its importance mentioned very often in this forum.

Steering stabilizers only mask symptoms of a bigger problem.

[nitroxsteve]

Did you say the steering wheel turns 1/8 turn before the tires move?

[81Chero]

O M G..  And this thing was supposed to have been owned by an aircraft mechanic!!

I just thought that maybe he didn't like cleaning the engine compt.

Never mind guys.. I know I found the issue($)  Off to Rock auto. By The way, pass side rotors have grooves deeper than 1/8 and 1/4 wide.

(I guess I didn't look that hard at the pass side. (It was raining.. REALLY)

Boy are those steering dampeners expensive! 

 

I'm almost embarrassed that I started this thread. It drove SO NICE for 2-days!  Then, BAM.

 

Thanks   E

 

P.S.  Yep, it turns about that much!  I already read of the XJ swap, and had that planned out.

It didn't matter to me with my mechanical skills and the price!!

[Eagle]

Never mind guys.. I know I found the issue($)  Off to Rock auto.

Respectfully, if you haven't yet done the repair and proven by a couple or few hundred miles of driving that you have no more death wobble, then you don't "know" that you've found the problem. What is it that you think is the problem, and what makes you so sure that's it?

 

Another thing is that the steering box is supposed to be a variable box. This one turns about 1/8 before the tires do, so maybe the XJ box swap is needed NOW! And maybe the whole problem with the wobble.?

Where did you hear that an MJ steering box is supposed to be a variable ratio box? MJs and XJs have always used the same steering box, and to the best of my knowledge they never used a variable ratio box. Even if they did, that wouldn't explain slop in the box -- that's most likely the over center lash adjustment. It can't and doesn't cause death wobble.

[Incommando]

The little u-joints on the column to box steering shaft can be worn or even broken and cause such slop. Not uncommon in the rust belt if nowhere else.

[81Chero]

 

Never mind guys.. I know I found the issue($)  Off to Rock auto.

Respectfully, if you haven't yet done the repair and proven by a couple or few hundred miles of driving that you have no more death wobble, then you don't "know" that you've found the problem. What is it that you think is the problem, and what makes you so sure that's it?

 

Another thing is that the steering box is supposed to be a variable box. This one turns about 1/8 before the tires do, so maybe the XJ box swap is needed NOW! And maybe the whole problem with the wobble.?

Where did you hear that an MJ steering box is supposed to be a variable ratio box? MJs and XJs have always used the same steering box, and to the best of my knowledge they never used a variable ratio box. Even if they did, that wouldn't explain slop in the box -- that's most likely the over center lash adjustment. It can't and doesn't cause death wobble.

 

Eagle:

1, NO disrespect taken sir. I finally got the chance to jack up the front and 'wiggle' stuff.. BOY, the d/s tie rod end moved almost 1/2" when I grabbed the p/s rotor and did a 3-9 tug.  12-6 tug didn't show any ball joint wiggle that I could tell. I ordered inner/outer tie rods and the pivoting rod end (like an Idler arm) just because I really don't want to be missing something and let that happen again. (ESPECIALLY to my son. That would freak him out to the point of he wouldn't drive it) 

When I pulled the p/s rotor off, another indication of poor mtc was not much grease packed in the bearing cup. (this was the one with bad grooves, it's getting replaced anyway)

2, In the past couple weeks, I've read what seems like thousands of threads from several dozen sites and would swear that I read that the Mj's were variable. And going to the Grand Cherokee's lessened the ratio to around 12:1. (I think I got that straight..) Just figured that because of the thought of being VARIABLE, that might be A cause of more slop in the box. In addition to all the above..

 

On my older Chevy's that I've had over the years, the rag joint replacement usually helps a good bit. But, there have been several that I've had to crack the jam nut on the steering box adjustment on top and give it a "slight" tightening. Depending on the miles, and if it was mostly city driving, the 'center' of the worm gear/steering rack will be just loose and there really isn't much you can do besides just replace which ever it is.

box or rack. Just because it's worn PAST a safe limit that's probably going to jam or ____.  

On the steering "U" joints, I'll take a look at those tomorrow afternoon. I'll try and put a vise-grip on both ends and do a little twisting and see how much play there is..

 

I struck MJ gold! I went to a yard (not really a pull-it type. just an ol country salvage yard) about 28yrs ago.. it's about an hour from me and was doing 'business' out there anyway. NOT 2, but 3 THREE! Comanche's. This place is HUGE--- There's NO WAY that the legend on the map is true. I was in the upper N/E corner and it looked like a half mile to the Southern end.. (if you had an 'accident' they wouldn't find you for weeks..) 

https://www.google.com/maps/place/Brown+Arvolle+Used+Cars+%26+Properties/@34.9184065,-88.6507002,385m/data=!3m1!1e3!4m2!3m1!1s0x0:0xd0be75c1a40080ec

Didn't think it was still there with all the cars that got scrapped to China.  Going back next week to get what I can.

 

When I went for the first test drive, it was raining for several days and there was a slight break in the clouds to take a drive. BUT I usually crawl under and take a look-see at damage, leaks, 'shade tree' repairs etc..

But there was puddles of water all over and I didn't look as close as I would have if it was dry out. (Did I say that i got a GREAT DEAL on it?)  I mean, i've paid more for cars that didn't even run, or have an engine..

 

I'll let you guys know with hopefully pics, if I can get them to Image shack ok.

 

Errol

[Eagle]

2, In the past couple weeks, I've read what seems like thousands of threads from several dozen sites and would swear that I read that the Mj's were variable. And going to the Grand Cherokee's lessened the ratio to around 12:1. (I think I got that straight..) Just figured that because of the thought of being VARIABLE, that might be A cause of more slop in the box. In addition to all the above..

The ZJ Grand Cherokee box is 12.7:1. Most XJ and MJ boxes are 14:1. The 1986 MJ FSM says that MJs with the off-road package had a 17:1 ratio. The slower ratio would be slower (:duh:) but that would not introduce slop -- it's just a slower ratio. I don't know how many years they used the slower ratio with the off-road package; I only have one (early) MJ FSM.