Death Wobble ?

[Robudda723]

Background: I got my 93 Jeep GC for dirt cheap after it side swiped a parked car. Fender damage and front suspension damage. I found one lower control arm was severely bent and the other 3 slightly bent. Also the axle brackets were bent. I originally had plans to slowly build over time with a new lift and such. However my daily driver took a crap on me and had to put this together fast. The fastest way was to buy an axle/control arms and all from a donor vehicle. I put new bushings in and bolted it up.

Today:I got the alignment very close (slight pull to right)and was planning on having alignment done at lunch work. 20min on the freeway and the Death Wobble strikes, and I thought the car was going to shake apart. I slowed it down pulled over and checked it. nothing looked out of place. start driving and seemed good till I hit 40mph and I can feel it start again. so Had to finish driving to work on back roads and home that way.

You can feel it start every time I hit 40+ mph.

Question: I am wondering since the wreck if other things are tweaked and the only way to resolve it is a long arm kit, since they are mounted in a new location. or if simply an alignment might resolve. I do not have much time or money at this point and may consider selling to someone who has more time and know how to resolve the Death Wobble. I need this on the road now since it is my only daily driver.

Sorry so long and thanks for any advice,
Rob

 

[jmaxj]

have someone sit in it and work the wheel back and forth while you look for ANYTHING loose in the steering, trac bar, and control arms. check unit bearings and ball joints also, all can cause death wobble. sometimes even a worn out steering stabilizer has been known to do it also.

 

[NoTrax]

On my 1996 grand, I had horrible wobble, I replaced all the steering, and tires.. I can tell that it definitely is still there.. But being absorbed by the tires. Seems it was real bad the less rubber I had on the tires.. So it'll be back.

I've heard it's due to the lifting and or changing of the geometry of the already worn in components. If you change the angles, anything from where it has worn in over the years, you end up with the wobble.

 

[jeeper]

A bad trac bar will do this for sure.. At least it has been the cause of ours on multiple vehicles.

 

[Craig S]

Caster, check your caster angle. You are looking for about 4-7 degrees negative caster. This means that the angle of your kingpins or ball joint tops tip back to the rear of the vehicle.

 

[RedeyeRacing]

Google the term "death wobble checklist". You will find lots of checklists on how to determine what yours is. IT CAN BE CURED.......

 

[ewander]

Were you coming back from Orem/Utah County earlier this week?

I saw a GC with MASSIVE death wobble. I'm sure the one I saw messed his ball joints up pretty bad (if they weren't shot already).

As was posted above, I would check the track bar first.

On my dodge ram it was the track bar, on my JK it was the track bar, caster, and control arm bushings.

Good luck!

 

[jeep-N-montero]

Rob, did you check your shorts after? We talked about this, get it to the alignment shop and make sure they check it it over thoroughly.

 

[Robudda723]

Rob, did you check your shorts after? We talked about this, get it to the alignment shop and make sure they check it it over thoroughly.

LOL, Sure did, and it didn't help with a big rig next to me and one behind.

I was asking because I have heard people mention this with lifts and such, and didn't even think about it with a stock setup. I was thinking that the brackets on the body may be tweaked and it was gonna be tough to fix.

Luckily my Fiance only works 10 min from house and no freeway needed. She is going to drive it since she will not be over 35mph to/from work, I am taking the Armada. I will keep working on it and replacing and tightening until it stops.

I guess time and money is all I need.

Thanks for everyone's input. New to the 4 wheel deal, all my experience is in drag racing and this is a whole new world.

Rob

 

[thenag]

this is a very good writeup on it.

I don't agree with him that a track bar is the only thing that can cause true death wobble, I have seen many a leaf sprung truck with death wobble... (i guess if it had a trac bar it wouldn't wobble?)

http://www.jkowners.com/forum/showthread.php?t=30723

The interesting thing he mentions is that one death wobble will wreck a lot of components so replacing one thing won't cure it and the next time it wobbles it will wear out the new part...

Also check the balance on tires, un-balanced tires will start a wobble that sucks

Nathan
-99 xj
build thread http://www.rme4x4.com/showthread.php?t=83436

 

[larrybenny]

On my 88 jeep wrangler (that I no longer have) as soon as I went from 33 in. tires to 35 in. tires, I immediately had a death wobble when hitting the slightest bump. I found that a new steering stabilizer shock fixed it (upgraded to a HD skyjacker). The old one wasn't totally bad, just worn enough to not perform well with the heavier and larger tire.

 

[Robudda723]

Lot's of good info.

Before going any further on the GC quick question. If the control arm brackets (Body side) got slightly tweaked in the wreck, Can I still get Death Wobble even if I replace/adjust everything else up front?

Thanks again for all the help and info.
Rob

 

[thenag]

Lot's of good info.

Before going any further on the GC quick question. If the control arm brackets (Body side) got slightly tweaked in the wreck, Can I still get Death Wobble even if I replace/adjust everything else up front?

Thanks again for all the help and info.
Rob

If everything is tight it shouldn't wobble even if it is bent, it will have other problems but a wobble is due to play in something.

Also a steering stabilizer cannot "fix" a death wobble, it will only "hide" a death wobble, if there is no play in anything it won't wobble with or without a steering stabilizer. I just went through this with my father in law working on my mother in laws stock GC, I finally convinced him to drive it without a stabilizer to make sure the DW was cured then put the stabilizer back on after he was sure DW was gone.

Nathan

 

[RockChucker]

rob, i used to have the death wobble problem in my jeep too. for me it was worn out tie rod ends, shot ball joints and tire balance. a steering stabilizer is just a mask, unless you talk to a certain 4wd shop here in the valley that thinks they are the end all cure all to death wobble and put 2 on. which still doesn't cure it in case you were wondering.

looking back on all my DW problems, i'm pretty sure that it originated with ball joints. and if your jeep got hit on the side, i can almost guarantee that they are shot, or you have a bent inner c or knuckle. i would check there. and balljoints are pretty easy to do as well. i did both sides in my jeep in about an hour and a half or 2 hours. you are mechanically inclined, so i think they would be no big deal. just get the loan a tool ball joint press at auto zone.

good luck.

 

[Robudda723]

Thanks all for the information. I will start on tracking it down this Weekend starting with alignment, and tire balance then go through and tighten and replace everything that needs it.

 

[jeep-N-montero]

rob, i used to have the death wobble problem in my jeep too. for me it was worn out tie rod ends, shot ball joints and tire balance. a steering stabilizer is just a mask, unless you talk to a certain 4wd shop here in the valley that thinks they are the end all cure all to death wobble and put 2 on. which still doesn't cure it in case you were wondering.

looking back on all my DW problems, i'm pretty sure that it originated with ball joints. and if your jeep got hit on the side, i can almost guarantee that they are shot, or you have a bent inner c or knuckle. i would check there. and balljoints are pretty easy to do as well. i did both sides in my jeep in about an hour and a half or 2 hours. you are mechanically inclined, so i think they would be no big deal. just get the loan a tool ball joint press at auto zone.

good luck.

Shoot, all a second stabilizer will do is raise the speed at which the wobble shows its ugly face, and that could kill someone at 70mph.

 

[larrybenny]

I worked at a Chrysler / Jeep dealership up to a couple of years ago, in the service dept. And I can't count how many NEWER jeep wranglers with low miles, tight front ends, and under factory warranty had to have the steering stabilizer replaced, especially with larger tires. Goes without saying everything else needs to be in good shape. My 91 Jeep with 5.3 conversion, spring over and high steer setup did not have a shimmy shock (stabilizer) on it when I bought it, and had a slight shimmy at 45 or so mph. I adapted a shock to it and now it drives perfect. Have had it up to 110 mph.

 

[RockChucker]

Shoot, all a second stabilizer will do is raise the speed at which the wobble shows its ugly face, and that could kill someone at 70mph.

actually i don't agree with this statement at all. There is a reason DW only happens at a very certain speed window. I have thought long and hard about this, and for all I know I'm up in the night, but here goes.

DW has to come from movement somewhere, and that movement is able to 'resonate' if you will, and get bigger and bigger. I think that is pretty well understood about DW. Here is where my theory comes in though, having experienced more DW than anybody should. As soon as you get above 55ish mph, the resonation is overcome by the centripetal force of the tires and they basically force everything to stay straight. You may experience a shimmy, but I have never had bone rattling DW above 55 mph. Like I said though, this is only my theory, based on my experience.

 

[anderson750]

actually i don't agree with this statement at all. There is a reason DW only happens at a very certain speed window. I have thought long and hard about this, and for all I know I'm up in the night, but here goes.

DW has to come from movement somewhere, and that movement is able to 'resonate' if you will, and get bigger and bigger. I think that is pretty well understood about DW. Here is where my theory comes in though, having experienced more DW than anybody should. As soon as you get above 55ish mph, the resonation is overcome by the centripetal force of the tires and they basically force everything to stay straight. You may experience a shimmy, but I have never had bone rattling DW above 55 mph. Like I said though, this is only my theory, based on my experience.

I have had DW in a 2500 Dodge with a worn out track bar at 70mph. Gets your attention pretty quick since the truck feels like it is going to come apart at the seams.

 

[thenag]

actually i don't agree with this statement at all. There is a reason DW only happens at a very certain speed window. I have thought long and hard about this, and for all I know I'm up in the night, but here goes.

DW has to come from movement somewhere, and that movement is able to 'resonate' if you will, and get bigger and bigger. I think that is pretty well understood about DW. Here is where my theory comes in though, having experienced more DW than anybody should. As soon as you get above 55ish mph, the resonation is overcome by the centripetal force of the tires and they basically force everything to stay straight. You may experience a shimmy, but I have never had bone rattling DW above 55 mph. Like I said though, this is only my theory, based on my experience.

The way I understand it is that if every thing is tight it can't resonate. Think about it for it to wobble something has to give. if ball joints, control arms, link arms, drag link/tie rod ends, are all tight even if you have big out of balance tires it shouldn't wobble.

nathan