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Diagnosing Death Wobble and Fixing Non-DW Shimmies and Wobbles

170K views 359 replies 103 participants last post by  orangecrush03 
#1 ·
Here are a couple videos. The first explains your front end. The second is an actual inspection.





I'll start out by explaining that Chrysler decided to use a 14 mm trackbar bolt, with a trackbar bushing sleeve designed for a 9/16" bolt, and the trackbar bracket bolt holes are somewhere around 15-16 mm large. This is a sure recipe for DW if the trackbar bolts are not properly torqued and periodically re-torqued to 125 ft. lbs.



Because my DW posts are buried in other members' threads and in some PMs, here is a thread of its own.

I will also include info on non-DW shimmies and wobbles in the thread.

I will clean it up as I go, but it should be helpful nonetheless.


Death Wobble is no mystery.

It is caused by loose bolts, damaged components, or improper installation.

Look at the picture below and follow along:



First, the tie rod (green) has ends that attach to a knuckle on each side. As you could imagine, if either ends of the tie rod were broken or bad, that could be a culprit for a shimmy (not Death Wobble). A common place to damage the tie rod is on the driver's side at the adjusting sleeve (in the picture, just to the right of the red swaybar link). That sleeve (maybe not the correct term for it, but you can see what I am talking about) allows the width of the tie rod to be expanded or contracted. There are threads on that end that can be damaged, causing play on that driver's side and allow an up and down, or circular play movement. Again, this would cause a shimmy, not Death Wobble.

Next, look at the drag link (purple). On one end, it attaches to the pitman arm (lavender), that attaches to the steering gear box. On the other end, the drag link attaches to the passenger side knuckle. When you turn your steering wheel, a shaft turns that goes to the steering gear box. The steering gear box turns the pitman arm, and the pitman arm pushes or pulls the drag link, which pushes or pulls the knuckle. Your steering wheel is straitened by loosening the two nuts on the sleeve/turnbuckle on the drag link and rotating the sleeve/turnbuckle to lengthen or contract the length of the drag link. If either end of the drag link is damaged, this would cause a wobble or shimmy, but not Death Wobble.

Next, look at the trackbar (aqua). It attaches to a bracket on the frame on the driver's side and to the axle on the passenger side. The purpose of the trackbar is to center the axle on the frame. With the axle centered on the frame, it provides some resistance to the steering system to allow you to turn. If there was no trackbar and you turned the steering, the whole front frame would shift. As a result, there is significant force applied to the trackbar in driving and steering.

Now, imagine that the bolts that hold the trackbar are loose in their bolt holes, or that the bolt holes are wallowed out (oval), or that the bushings at the trackbar ends are damaged, or that the bracket at the axle side has come loose because the weld has broken, or that the bushings are all twisted up because the rig has been lifted without the installer loosening the bolts and then retightened them at the new ride height. All these things would allow play in the front trackbar. When you steer or go around a corner, these loose or broken things would allow the axle to shake or slide side to side. If you hit a bump in the road, it could knock the trackbar towards the driver's side. Then, the rest of the suspension (springs, etc.) would try to bring the trackbar back to the passenger side. If you were going at any sort of speed, you could develop a kind of harmonic resonance as the axle more and more violently slide/rocked/shaked from side to side. It would feel like your whole front end was being voilently torn apart. You would have to bring your vehicle to a complete standstill to stop the harmonic resonance. This is Death Wobble.

Even one incident of violent Death Wobble related to the front trackbar can cause significant damage. The voilent harmonic resonance of the back and forth shaking is more than the trackbar bushings, bolt holes, and brackets are designed to handle. A severe Death Wobble occurance can crack or break the welds on the axle side trackbar bracket, or the bolt can wallow out the bolt hole in the bracket, or the bushing can be permanently damaged.

This is the most common source of Death Wobble because inexperienced installers either do not remove the bolt from the trackbar when they install a lift--leaving the bushing pinched in the bracket and bound up, or they do not properly torque the bolts after the lift has been installed with the tires on and the full weight of the vehicle on the ground at ride height, or (maybe the most common) they do not retorque the trackbar bolts after the first 50 miles, after every heavy wheeling trip, and at every oil change interval.

Next, look at the lower control arms (purple) and the upper control arms (light blue). In the picture, they are aftermarket arms with a heim joint on one end. However, the stock control arms have a rubber bushing at each end. When the control arms are properly torqued, the bushing is somewhat pinched in the mounting brackets on the axle and the frame. Sometimes, an installer will make the mistake of not loosening the bolts for the control arms when they install a lift. What happens sometimes is they really bind up the bushings because they are pinched/sandwiched at stock ride height, but then forced to the new lifted ride height. These bound up bushings can cause weird handling, bushing failure, and lead to Death Wobble. The proper way is to loosen the bolts, install the lift, reinstall the wheels so the suspension and jeep are at the new ride height, rock the vehicle/suspension back and forth and side to side, then re-torque the bolts to spec, then after 50 miles re-torque them to spec, then after every oil change or very heavy wheeling trip re-torque them to spec.

Improperly balanced tires, too much air in tires, bent wheels, improperly installed wheel spacers, bad tires (with separated plys), and poor alignment specs (caster, camber, and not enough toe-in) can cause wobbles and shimmies that lead to Death Wobble. However, these precipitate Death Wobble, but they are not the cause of Death Wobble.

Although not specifically identified in the picture, the ball joints that are at the top and bottom of each knuckle where it attaches to the axle C can go bad. Bad ball joints can cause shimmies, wobbles, but usually not full on Death Wobble.

Next, allthough not identified in the picture, the unit bearings can go bad and be a cause of shimmy and wobble, but not Death Wobble.

Hope this helps--assuming you read it all.

Death Wobble is no mystery.

The reason that the steering stabilizer masks it is that it can absorb some of the side to side voilent harmonics of a loose trackbar or damaged mounts. However, this masking is dangerous because it will not prevent the eventual failure of trackbar bracket welds and bolt holes from trackbar Death Wobble.

It is extremely important to immediately diagnose and fix Death Wobble.

Even one episode of DW can damage other components.

Multiple episodes of DW are almost guaranteed to damage other components.

Multiple episodes will often damage your:

  • ball joints
  • tie rod ends--including the adjusting sleeve end on the driver side
  • trackbar bushings
  • trackbar bracket bolt holes
  • steering sector shaft (where the pitman arm attaches to the steering box)
  • steering stabilizer
  • front lower control arm bracket bolt holes
  • unit bearings
  • trackbar bracket welds
  • drag link ends

Hellbound13 is an example of a member who with 5-6 episodes of trackbar related DW on a stock jeep ended up "chasing his tail" for many, many months. He ended up replacing almost everything in the above list--sometimes more than once.

Without repairing/replacing everything that was damaged at once, the remaining damaged components continued to cause DW problems, further damaging the remaining components.


This is Death Wobble (and the guy is extremely foolish for repeating it on purpose):

 
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#208 ·
So I have been dealing with a wobble/ shimmy in my Jeep. Started out very slightly after the new (used) tires. So I pulled them back off, checked my wheel adapters, and started to rotated the tires around to track down which tire was causing it.

Found one of the tires on the front was bad so I went to a friends tire shop to have them re balanced. In doing so I found out 2 of the tires are slightly out of round. Those 2 are now on the back. The shimmy was 10 times better, but still there. Only happened at about 40-47 mph. Anything higher or lower and it was gone.

So I added balancing BB's to the tires. They made the ride a lot smoother and even made the shimmy better, but didn't completely cure it. (Keep in mind I've been checking all the steering components through each step, no play in tie rod ends, drag link ends, or track bar ends).

The yesterday on a long drive towards the beach I made a left turn and started to speed up and the shimmy/ wobble got 10000% worse. At about 30 mph I couldn't drive it. As soon as I would drop below 30 it would stop. I knew it wasn't death wobble. After making it home I tried to find a loose component and couldn't find anything. So I bought new ball joints.

After removing the old ball joints, the lowers where bad, and the uppers where fine. I changed all 4 anyways. And again checked for play in all the steering and suspension. Everything is tight, no play, and torqued. I am now back to a very slight shimmy at 40-47 mph that sometimes isn't there at all. Could this be a toe issue? Last time I checked it with the tape measure I was at 3/8" toe in.

Just want to ask if this will trash my new ball joints or if the slight shimmy is something I can drive with for the next 10,000 miles until the used 40's wear out and I can get some new ones.
 
#209 ·
Ok I was fine up till 2 weeks ago. I was wheeling and smashed my passenger front tire hard enough o bend my rim and bend my track bar. Replaced the track bar and moved the bent tire to the spare. Since this I have a speed dependent wobble at 50 MPH. Prior to this it was fine. So I am thinking something is up with my spare that I put in the front. All my tires are very worn.

But here is my question. If an unbalanced tire will not cause the DW why in the first step are you advised to rotate your tires? If this cures it it is only a band aid fix, gathering what I read, there is still an underling problem which will come back.
 
#210 ·
Again, speed dependent wobble is NOT death wobble. That's not what we are talking about here. If your wobble comes and goes with speed change, something is out of round or out of balance. If you hit a bump in the road and your Jeep tries to shake the front end to pieces and you cannot control the vehicle without pulling off the road, THAT'S death wobble.
 
#212 ·
Wow! Wish I had found this a year ago. At the time, I hadn't thought of calling it a Death Wobble, but I can attest to that being a very apt description.

For us, it was a repeatable thing. I knew the exact place on the road outside our house to make it replicate. It was a harmonic kind of thing, if you got the bounce just right, at the right speed (about 45 for us), then the front end felt like it wanted to take off into the weeds but couldn't figure out which side of the Jeep to leave from.

The Steering wheel was a handful. If it hadn't been for two hands on the wheel the first time we felt it... I don't know we'd have recovered. So here's where it gets weird.

We take it to a trusted local shop. They tell us to replace the tires, because they are badly worn on the outside edge. Their inspection of everything else doesn't find anything.

So I'm thinking to myself... tires don't wear "funny" just on their own; something causes it.

We order new tires and have to wait for them to come in. During the few days we wait, I take an ingenious keyfob video camera and tape it to the bottom of the axle and get some great video of the problem.

Yes, the track-bar was loose, but in addition, the passenger side lower control arm was found with really bad bushings. The video showed the passenger side was absolutely violent when compared to the driver's side.

The problem now... we replaced the tires and I replaced the bad bushings in the control arm. The DW is now gone, but we can still pick up some shakes in about the same part of the road. This tells me I don't have it completely solved, in that the original DW has probably caused a lot more parts to get out of whack.

And the tires are already starting to wear funny, which is my second indicator that something still isn't right. Having read the first few posts in this thread, I'm now sure of what I need to go back and inspect, and I feel a lot more confident it's something we can fix.

I'll probably also print out the first few posts and take it to my trusted shop. They are good old boys, but that may be part of the problem too... good and old... and technology challenged. Probably haven't seen it quite this way before.

Asa Jay

PS. This same thing happened to my Dad's 1993 Dodge pickup truck, with me driving. The Dodge dealership he takes it to found the problem right away and fixed it. No problem since.
 
#214 ·
So glad I found this thread. I have a 2011 stock Wrangler and went around the corner on PCH the other day and all of sudden the Death Wobble. I didn't know what was happening.

I have a full 100k warranty bumper to bumper. How should I proceed?
Read posts 1 and 2 of this thread: http://www.jeepforum.com/forum/f96/diagnosing-death-wobble-fixing-non-dw-shimmies-wobbles-1052221/

Then, watch my 2 YouTube videos that I posted in the following thread:
http://www.jeepforum.com/forum/f96/diagnosing-death-wobble-non-dw-wobbles-shimmies-videos-1376201/

You will know and understand more about DW and your front end than your dealer techs.

It is rare that a dealer tech will know what to do. So, your warranty doesn't hold much value to fix the problem(s). You can try, but don't get your hopes up.
 
#222 ·
planman

I have an 2009, 19,000 miles, that is going to my mechanic next week for the DW fix. I told him to follow your complete list, word for word. I ordered the bolts as you suggested, and would like to get a heavy duty steering stablizer. Can you recommend a source and description for this item? Also, are there any other parts I should order before the inspection/fix?

Your instructions for the DW fix are most appreciated!!!!!!! I experienced the DW about a week ago and was ready to sell my Jeep until I found this forum. Thanks again.
 
#225 ·
I have an 2009, 19,000 miles, that is going to my mechanic next week for the DW fix. I told him to follow your complete list, word for word. I ordered the bolts as you suggested, and would like to get a heavy duty steering stablizer. Can you recommend a source and description for this item? Also, are there any other parts I should order before the inspection/fix?

Your instructions for the DW fix are most appreciated!!!!!!! I experienced the DW about a week ago and was ready to sell my Jeep until I found this forum. Thanks again.
I don't really have a specific recommendation on a replacement steering stabilizer.

The only exception would be that if you run Toyo Open Country MT tires that result in a hard drift to the right even with an alignment, you can offset this by running a gas charged steering stabilizer that pushes towards the driver side.

Otherwise, you could do a combination relocation bracket and new steering stabilizer from any number of manufacturers.
 
#223 ·
mcduff said:
I have an 2009, 19,000 miles, that is going to my mechanic next week for the DW fix. I told him to follow your complete list, word for word. I ordered the bolts as you suggested, and would like to get a heavy duty steering stablizer. Can you recommend a source and description for this item? Also, are there any other parts I should order before the inspection/fix?

Your instructions for the DW fix are most appreciated!!!!!!! I experienced the DW about a week ago and was ready to sell my Jeep until I found this forum. Thanks again.
Make sure it's fixed before you put a new stabilizer on, otherwise it is going to mask the real issue.
 
#226 ·
So I purchased an 00 XJ with a cobbled together RCX lift and serious death wobble problem that made it not drivable. It had stock UCA that were bent and one of the bushings shot. I replaced the UCA with Rusty HD flex control arms and changed the bushings and that improved things and it's now drivable. However I still have DW if I hit a large bump at highway speeds (60+mph) with only one tire. If bumps are hit head on with both sides making contact no shakes.

I went through the check list I found in this thread and everything seemed to check out ok with the exception of a broken passenger side shock (shock bushing is bad and the body has a large dent in it) so I ordered some Bilstein 5100's to replace then.

I am skeptical that a simple shock can throw this thing into such violent DW event and wondering if you guys think I missed something.
 
#227 ·
So I purchased an 00 XJ with a cobbled together RCX lift and serious death wobble problem that made it not drivable. It had stock UCA that were bent and one of the bushings shot. I replaced the UCA with Rusty HD flex control arms and changed the bushings and that improved things and it's now drivable. However I still have DW if I hit a large bump at highway speeds (60+mph) with only one tire. If bumps are hit head on with both sides making contact no shakes.

I went through the check list I found in this thread and everything seemed to check out ok with the exception of a broken passenger side shock (shock bushing is bad and the body has a large dent in it) so I ordered some Bilstein 5100's to replace then.

I am skeptical that a simple shock can throw this thing into such violent DW event and wondering if you guys think I missed something.
I think Planman checklist is great for a decent setup vehicles that have normal wear and tear. It sounds like your XJ has serious collision issues that were never fixed and probably contributed to your DW woes.
 
#229 ·
planman said:
It is more than just the single shock.

You may need to pull components off (one at a time) to inspect bracket bolt holes and bracket welds--particularly the trackbar.

Did you check the ball joints?

Were the front upper axle side bushings worn or separated (the ones in the axle housing)?

Were the upper control arm brackets bent, welds cracked, or bolt holes ovaled out?

What about the drag link and tie rod ends, and the steering box (notoriously weak in stock form for lifted XJs with larger tires)?
The ball joints are newish within 6 months, the tie rod ends look old but don't appear damaged and there isn't any play so I haven't changed them out yet. Although the stock tie rod seems pretty flimsy as I can make it bend by hand, the drag link however looks like it may be adjusted since the rod end on it looks like its under a bind (I can't feel it bind or hear it popping though) but the alignment shop of course probably over looked this.

The UCA on the driver side was bent out from under neath, it looks like something struck it off road I am guessing and bent the Fischer Price grade stamped steel and yes they (the axle side bushings) were worn so they were replaced when I installed the new control arms.

The track bar is some cheap aftermarket adjustable one probably came with the RCX lift and the stock bolt has been replaced with a larger one. It looks like the PO ran the stock track bar for awhile though because of the hole drilled to the port side of the track bar mount.

I should note that the DW is very particular in what bumps set it off. I have driven from Mobile to NOLA about 3 times (300 miles round trip each time) in one week and only experienced 2 DW incidents.
 
#230 ·
rebelbowtie said:
The ball joints are newish within 6 months, the tie rod ends look old but don't appear damaged and there isn't any play so I haven't changed them out yet. Although the stock tie rod seems pretty flimsy as I can make it bend by hand, the drag link however looks like it may be adjusted since the rod end on it looks like its under a bind (I can't feel it bind or hear it popping though) but the alignment shop of course probably over looked this.

The UCA on the driver side was bent out from under neath, it looks like something struck it off road I am guessing and bent the Fischer Price grade stamped steel and yes they (the axle side bushings) were worn so they were replaced when I installed the new control arms.

The track bar is some cheap aftermarket adjustable one probably came with the RCX lift and the stock bolt has been replaced with a larger one. It looks like the PO ran the stock track bar for awhile though because of the hole drilled to the port side of the track bar mount.

I should note that the DW is very particular in what bumps set it off. I have driven from Mobile to NOLA about 3 times (300 miles round trip each time) in one week and only experienced 2 DW incidents.
You need to watch the 2nd video in the 1st post of this thread.
 
#231 ·
planman said:
You need to watch the 2nd video in the 1st post of this thread.
Ok so I didn't think to saw the steering wheel back and forth so quickly, I had been moving it slowly from lock to lock. I will go out and inspect some things using your methods.
 
#233 ·
hi guys. im expecting a bit of just do what the first post says, however at the moment i have no friends who can come round and move the steering wheel for me.

ive got an 07 2dr rubicon with 2.5" rockkrawler springs, aev front control arm drop brackets, bilstein 5100s but dont have trackbar brackets (rear teraflex is on its way)

ive got some wobbles that come in at 90km/h and seem to dissipear by 100kmh and arent there below about 85km/h either. i've gone around and just physically tightened everything i can but so far is without help.

i have noticed though that its become a pretty bumpy ride all round. hitting any sort of bump at 40km/h + throws me around in the cabin more than it used to. i have had the lift kit in for about 2 months and only started having this issue about a week ago.

anyone have an idea of where i can look by myself?

cheers
 
#234 ·
lima_been said:
hi guys. im expecting a bit of just do what the first post says, however at the moment i have no friends who can come round and move the steering wheel for me.

ive got an 07 2dr rubicon with 2.5" rockkrawler springs, aev front control arm drop brackets, bilstein 5100s but dont have trackbar brackets (rear teraflex is on its way)

ive got some wobbles that come in at 90km/h and seem to dissipear by 100kmh and arent there below about 85km/h either. i've gone around and just physically tightened everything i can but so far is without help.

i have noticed though that its become a pretty bumpy ride all round. hitting any sort of bump at 40km/h + throws me around in the cabin more than it used to. i have had the lift kit in for about 2 months and only started having this issue about a week ago.

anyone have an idea of where i can look by myself?

cheers
Do you have more than 32psi in your tires?

If you have aftermarket wheels or wheel spacers, did you remove the lug retainer clips?

Speed dependent wobbles are nearly always tire/wheel related--out of balance, bent wheels, failure to torque non-hubcentric wheels in a star pattern, a bad tire, etc.

You absolutely must get longer front swaybar links if you ever use the electronic Rubi swaybar disconnect. With longer rear shocks, you absolutely must either use rear brakeline drop brackets or run longer rear brakelines.
 
#236 ·
hey mate thanks for this.
i just noticed it because i came back on to say i fixed the problem. went through planmans guide and just tightened everything. no good everything was pretty tight. thought i don't think its a wheel inbalance because i would expect that to be there at all speeds but hell ill rotate fronts to rear anyway. and BAM fixed! so needless to say i still have an out of balance tyre onthe back i need to get balanced but im glad its not loose bolts. so well done for the correct diagnosis mate!

also as an addition, i forgot to mention with my lift kit i bought the teraflex 2.5" spring lift kit, swapped out the springs for rockkrawler springs and shocks for bilsteins.

so my front swaybar links are the factory rear ones and i have brake like relaocation brackets from the tf kit.

the only reason i dont have a rear trackbar bracket is because they sent me one for a LHD not RHD so it's currently in transit.

thanks for your help guys greatly appreciated.

on another sidenote, do you guys loctite (threadlock) your suspension bolts? i noticed they're not from factory but im thinking of redoing them all with threadlock to try and prevent any premature loosening.

ta
 
#235 ·
Also, your weird side to side sway would be aggravated by too short swaybar links.

If you did not loosen every control arm and trackbar bolt, and then wait to retorque all bolts until the full weight of the jeep was back on the ground at the new ride height, your rubber bushings are twisted/binding/pre-loaded to the wrong ride height. This will result in a jittery ride and pre-mature bushing failure.
 
#238 ·
also i dont know if im dreaming this because i can't always replicate it. but it seems sometimes if im under load e.g part throttle in gear and back off the throttle and depress the clutch to change up gear, the car seems to veer a little bit to the drivers side. would this be typical of non loosened control arm bushes? i'm pretty sure i did do it hoever i put aev drop brackets in later so may have missed the chassis side bushes when i put them in.
 
#240 ·
also i dont know if im dreaming this because i can't always replicate it. but it seems sometimes if im under load e.g part throttle in gear and back off the throttle and depress the clutch to change up gear, the car seems to veer a little bit to the drivers side. would this be typical of non loosened control arm bushes? i'm pretty sure i did do it hoever i put aev drop brackets in later so may have missed the chassis side bushes when i put them in.
Could also be the trackbar drop brackets you haven't put in yet? (seems possible)
Or the uneven load placed on the anti-swaybars due to the too-short links? (maybe less likely, but still possible perhaps?)

And do you have a locker or limited-slip in the rear? I don't remember what the option was for your year, but if an electric locker, could it be engaged?
It sounds like a very mild version of what can happen with a Detroit Locker, so maybe the factory locker/limited-slip is the culprit?
Probably less likely than the first two, but thought I'd mention it anyway just in case.

Then again, it could just be as you and planman suggested about any uneven loads on the control arms.

Just throwing out total guesses of course. But figured another 2¢ worth of useless suggestions would get the creative detective juices flowing.

Best of luck!

Paul
 
#241 ·
Thanks guys just a reminder that my sway bar links are not too short. My stock rears are in the front. Also loosened my control arms and happy with the outcome doesn't seem as jittery. Only minor issue I have left now is when I hit bumps eg like rail road tracks and bounces the front end a bit, I can feel the front end wobbling a bit. Didn't throw me around. I just feel it wobble for half a second before going back to normal. Ta
 
#242 ·
... Only minor issue I have left now is when I hit bumps eg like rail road tracks and bounces the front end a bit, I can feel the front end wobbling a bit. Didn't throw me around. I just feel it wobble for half a second before going back to normal. Ta
That is probably your steering stabilizer fixing another problem. I'm no mechanic; but, letting your SS solve problems is not a good idea. Realistically you should be able to drive (even over bumps), without any wobble, without having the SS on your Jeep. :2c: I'd recommend continuing to look for the problem.
 
#244 ·
dualtjs said:
Planman,

Are you getting royalties from Northridge4X4? They linked your youtube video, in their product page for the bolt upgrade kit that they sell:

http://www.northridge4x4.com/shop/nr4x4-jeep-jk-hardware-kit
No. No royalties or compensation.

Although, I initially brought the issue to their attention and sent them a link to my video. They subsequently put together the kit.

They did send me 2 kits to test out. I believe they include a kit at no charge for people who buy a full suspension lift from them.
 
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