Intense death wobble

[Master7122]

So i recently had gotten what i think is death wobble. My truck will act perfectly normal at any speeds but once it hits a series of bumps or big bump (happens above or at 40mph) the steering wheel will shack violently and the truck will bounce up and down rapidly until i slow down to 5mph then it will return to normal. The whole truck cab shacks and it feels as if the dash is going to fall into your lap. The truck has new shocks may i add

[Eagle]

That's death wobble. There is no consensus as to what causes it, unfortunately, so you'll have to do some sleuthing.

 

Is this a new phenomenon? How long have you had the truck and how many miles have you driven it? What has changed? New tires? Different alignment? Lift?

 

???

[Master7122]

Had the truck a couple months, has 92k I’ve driven it about 400miles. No lift, no new tires. The track bar mount was loose and i tightened it up and it still does the death wobble

[GreasemonkeySC]

Death wobble is almost always caused by a worn steering joint, weak track bar bushing, or lose hardware in the steering system.

 

With the vehicle running...... Do not touch moving parts!!!

Lay down in front where you can see the steering joints, hardware, and bushings. Have someone wiggle the steering slowly at first as you look for possible failed parts, then more aggressively when you think you have spotted the culprit.

It is possible to have multiple parts failing, or loose hardware combined with failing parts.

 

BTW: That track bar bolt needs to be tightened up by a meat & tater eating farm boy with a low IQ.

"Yeah, that tight"

[Eagle]

1 hour ago, GreasemonkeySC said:

Death wobble is almost always caused by a worn steering joint, weak track bar bushing, or lose hardware in the steering system.

 

 

And this is why I said there's no consensus on what actually causes death wobble. I've driven for periods of six months or more with a VERY loose, sloppy track bar when it was too cold and snowy to  think about changing it. Sloppy steering, but not a hint of death wobble. No matter how much I think about it, I keep coming back to the fact that a rolling tire is a gyroscope. There's simple no way that loose steering components can cause death wobble. My belief is that it's usually tire balance that causes it.

 

Ultimately, you have to check everything and just keep eliminating possible causes until you hit the one that works.

[DirtyComanche]

3 hours ago, GreasemonkeySC said:

Death wobble is almost always caused by a worn steering joint, weak track bar bushing, or lose hardware in the steering system.

 

Not really.  See Eagle's comment.  IMHO it's as likely, if not more likely, to be caused by worn control arm bushings or ball joints as it is steering parts.  The track bar/brackets seem to be the most common suspect though, but even if worn out they may not specifically cause issues.  Typically it's cumulative wear/stackup of tolerances, as in everything is worn a bit and not one part is really what's throwing it over the edge.

 

Basically look at things and start replacing stuff with whatever looks the worst or has the most play in it, repeat until the issue goes away.  Make sure the tires are balanced and haven't developed a bulge or tread separation, and the wheels are true.  Look for the track bar bracket egging out the hole on the axle, along with cracks on the uniframe by the steering box and frame side track bar bracket, or the steering box spacer breaking or the bolts coming loose.  Upper and lower control arms, make sure the bolts are tight, the holes aren't egged, and the bushings aren't failing.

 

It is a good time to do some upgrades though.  I'd order the new style XJ/ZJ steering parts, WJ lower control arms, new stock uppers/bushings, and a new style track bar and frame side bracket (might have to junkyard the bracket).  If the wheel bearings and ball joints are worn I'd do them and probably do the u-joints in the axle shafts (or buy CVs) at the same time.  I'd highly consider going to the new style knuckles/brakes/wheel bearings at that time.  All of this is assuming I planned to keep the truck for a long time and wanted it to be nice, but did not plan to lift it.

[GreasemonkeySC]

Sorry, I got my threads confused.
Very easy to do with the app. It doesn't separate forums very well, so I see posts from 5 different forums.
I was actually going over this with someone else that had already eliminated the tire balance possibility.
And you are correct that you must start inspecting the possible causes, and eliminate them as you go!

#1 tire balance
Also be sure it's done by a reputable shop. I've seen freshly balanced tires come in the shop and be a 1\4oz or more out of balance.

#2 loose hardware
Track bar bolt, linkage nuts, I've even seen steering gears not tightened up to the frame.

#3 steering linkage
This includes something that even mechanics will overlook. Your steering gear, and steering shaft. (My TJ had a faulty steering shaft support bearing, and I left to much slop in my gear when I rebuilt it. The 2 issues together caused wobbles, and a stiff spot in the steering.)

[JeepSchmidt O'Guinness]

....don't forget #4 suspension.

 

Start sleuthing, I only scanned the previous comments but didn't see suspension as a culprit. It was the cause of my run in with death wobble.

 

It would happen when downshifting the m.trans. After replacing the front shocks, I could take it out of gear without the fear of a wobble tantrum.

 

 

[75sv1]

I am going through this. In my instance, I think it is the rear springs. I do not get the vibes through the steering though. I did squirt some oil in the rear leaf springs. This helped a bit. The set of rear leaf springs dose not have anti-friction pads.

[Wounded_Fighter]

10 hours ago, GreasemonkeySC said:

BTW: That track bar bolt needs to be tightened up by a meat & tater eating farm boy with a low IQ.

"Yeah, that tight"

Lol.

That kind of tight that says "I'm Given her all shes got captain!"

But then you get the cheater bar out?

[GreasemonkeySC]

....don't forget #4 suspension.

Wow!
Yeah....1am was not being kind to me!

[GreasemonkeySC]

I am going through this. In my instance, I think it is the rear springs. I do not get the vibes through the steering though. I did squirt some oil in the rear leaf springs. This helped a bit. The set of rear leaf springs dose not have anti-friction pads.

Does your wiggle feel like it's in the seat of your pants? That's generally a sign that it's in the rear of the vehicle.
You need to check wheel balance, drive shaft joints, spring bushings, and axle bearings.

[75sv1]

5 hours ago, GreasemonkeySC said:

Does your wiggle feel like it's in the seat of your pants? That's generally a sign that it's in the rear of the vehicle.
You need to check wheel balance, drive shaft joints, spring bushings, and axle bearings.

Had it aligned a few months back. They did balance the wheels. A lot of new parts. Basically, a new front end. The present rear leafs are only 2-3 years old. I will have to check the shackle bushings. I thought I had a new one put in. I do have OME springs to put in. Its more than a wiggle.  I have not checked the shocks, but they are only 2-3 years old and Bilsteins.

       Edit: I did a search on the Net. One thread mentioned the pitman arm. I am at 4.5 lift on the front. I had a Rusty's track bar on it originally. I used a '95 GC pitman arm. About Christmas time, I had the front done with WJ Big Brakes and cross over steering. Also, used a Rusty's OTK track bar. Also, a Ford 8.8 was installed. So, I should probably check the drive shaft length. I did do a Hack-n_tap with a 8.25.

      Sorry to Hijack the OPs thread.

[JeepSchmidt O'Guinness]

9 hours ago, GreasemonkeySC said:

 

 

Wow!
Yeah....1am was not being kind to me!

 

Yeah, predawn wasn't having a good affect on me either. 

[SVPete]

My issue used to rear its head around 55 mph and was initiated by a hard bump like yours is. I could "feel" it wanting to wobble through the steering wheel when at that speed, it just needed something to set it off.

 

Haven't had a problem for a few years. Things I've done that may have had an impact:

1. Tightened track bar (then replaced it), although it didn't seem loose.

 

2. Replaced transmission mount (as I think about that when typing this....if the transmission mount is trashed..... I could feel the transmission "twist"  through the gearshift when I would release the clutch....and you hit a big bump, which may jolt the whole truck.....how does that impact the driveshaft spinning fast enough to go 55 mph, or 40 mph, with a basically non-existent transmission mount? Somebody smarter than me may know whether that can create the terrible vibration.)

 

3. New tires and balanced (old ones needed to be replaced, but then I had worn out a couple of sets while having the problem. To clarify, tire wear was normal.)

 

4. Regular lubing of suspension with every oil change (I realized that the oil changing shops were not really lubing the suspension and u-joints like they supposedly claimed to. The top ball joint is likely impossible to grease without taking the tire off. I had to clean so much gunk off, that I couldn't even determine if there was a zert there. The tie rod ends aren't easy to do with the tire on either. And since you have to move the truck to rotate the rear drive shaft to lube the u-joints, those weren't getting done also.)

[8valvehero]

Eagle is correct: Death Wobble is a generic symptom. 

I replaced everything under my truck and got DW beause of a sloppy OE steering box and slightly uneven tire wear. Before I replaced everything, it was all clapped out but had no DW.

 

Crawl under there while a buddy quickly turns the steering wheel back and forth a few inches.

Take your time to feel every joint and look hard for play.

 

Edit: don't forget about tie rod twist if you have big tires.

 

Good luck!

 

 

[75sv1]

An update:

          I took a trip to WV this past week. Going around Cincy , I hit a few pot holes. I had to pull over  and stop, so the shaking would stop a few times. It happened other times along the trip. Before coming back, I remembered I had not retorqed the spacers. I had a Ford 8.8 installed ,and WJ front brakes. Both required spaces as I am using 15 X 8 Canyon rims. The spacers were not loose, but some of the nuts needed about a 1/4 turn or so. I did not have any real issues on the return home except a few who might have wanted to test my Logans front bumper.

         That's the short story. Then there's saving a box turtle, which might have help me save my motor as there sprung a hole in my radiator. Blue Devil radiator stop leak to the rescue.

[Master7122]

I was able to stop my death wobble (so i think) by tightening my track bar mount. All four bolts were loose, and by loose i mean 1 thread till coming off....

[75sv1]

6 hours ago, Master7122 said:

I was able to stop my death wobble (so i think) by tightening my track bar mount. All four bolts were loose, and by loose i mean 1 thread till coming off....

Ouch, When I had my lift installed , I bought used parts. The track bar bushing was actually slotted from use. I think the previous owner only off road about 5 times.  The steering would jump a bit from side to side. Not really death wobble though.

[75sv1]

I just experienced Death Wobble again today. I hit a seam coming across a local bridge. I would say it was 1/4-1/3 less than before. I do have Yukon C-Clip eliminator kit on order, to get rid of the spacers. I do have a Ford 8.8 rear end with Limited Slip. I am wondering if this could be partially due to the LS.

[Eagle]

Death wobble affects the front. Nothing about the rear axle contributes to death wobble.

[hakukamana]

I had a customers Ford f150 truck that had death wobble like your describing, about a 6" lift, big tires, and a lot of abuse. Didn't happen until you hit that certain pot hole,  or unevenness in the roadway. We could not figure it out until we looked at the frame, yes the frame of the truck was cracked. I know MJ's are a unibody, but take a look at where things are connected to the unibody, a flange, a mounting point, if you can get the mud, undercoating, and what ever else is on there off. It may reveal a weak, cracked or broken, mounting point for your steering or suspension.

[Crash]

Aside from what has already been recommended. Do a tape measure alignment. Adjust toe if necessary, drive it.
The times I had DW, were toe, and worn tre related. First time was after a 2ish inch budget lift, adjusted toe went away.
I upgraded to the IM4x4fab tie rod after that as well, along with a used RE adjustable track bar.

Then, when I lifted my MJ, no matter what I did with my stock tre it had awful DW. Used my old IM4x4fab tie rod, went away.
I now have a WJ D30 in the front with crossover steering.

[75sv1]

I drove it this morning. Had a few instances of DW. Felt it in the front. I also heard a grinding noise. Seemed in the front passenger side. Still, I went through some drive shafts some months back. Looks like I have my work cut out. I am wondering if the Transfer Case could be loose, and taking out the drive shafts. Its the only part not new or rebuilt. I did look at the axle shafts, but the passenger side seemed OK.

[Eagle]

11 hours ago, 75sv1 said:

I drove it this morning. Had a few instances of DW. Felt it in the front. I also heard a grinding noise. Seemed in the front passenger side. Still, I went through some drive shafts some months back. Looks like I have my work cut out. I am wondering if the Transfer Case could be loose, and taking out the drive shafts. Its the only part not new or rebuilt. I did look at the axle shafts, but the passenger side seemed OK.

 

Are you really talking about death wobble? Death wobble is in the front end, and it's characterized by shaking of BOTH front wheels so violently that you almost can't hold onto the steering wheel and you're sure you're going to die, like RIGHT NOW.

 

If your life isn't replaying before your eyes while you pray you can stop before the truck is thrown violently off the road -- it isn't death wobble.

 

No, I am not exaggerating.