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Diagnosing Death Wobble and Fixing Non-DW Shimmies and Wobbles

158K views 217 replies 72 participants last post by  TheSecretSavage  
#1 · (Edited)
The Inspection Checklist is in Post #5 of this thread.

Most people would benefit from watching these two videos. The videos are kind of long at 18-19 minutes each. Hopefully, they are thorough enough to help.

PLANMAN explains Death Wobble Diagnosis and Inspection Jeep JK Wrangler Part 1 - YouTube
Part 2, PLANMAN explains Death Wobble Diagnosis and Inspection Jeep JK Wrangler - YouTube

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.

Stock JK bolt in stock trackbar bracket hole - YouTube

HITMONEY suggested I do a Death Wobble Write Up Dept. thread.

It is a good suggestion because my DW posts are buried in other members' threads and in some PMs.

So, here are some of my posts and PMs regarding DW.

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:

Image


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):

Death Wobble - YouTube
 
#136 ·
I'm on a mission before the 2500 mile road trip!


Sent from my iPhone 5!
 
#137 ·
Just wanted to say thanks Planman.

I replaced my stock crap bolts with 9/16ths 3" long grade 8 shouldered bolts, grade 8 locking washers and nuts.

I had only about 2-3K miles on my aftermarket trackbar and the sleeve in the bushing definitely was ribbed from the crap stock bolts. The bolts were loose in the sleeves also and were tightened to 125lbs.

The reason I did the swap of bolts was because my Jeep was starting to show signs of early death wobble (Only 18K miles on her too). When I would hit any bump at speed, the steering wheel would jolt/shake. So before it did turn into death wobble/or getting any worse, time to fix it for good.

After replacing with the new bolts....it is like driving a different vehicle. The steering feels so much tighter. No more jolting of the steering wheel when hitting bumps. Man, I wish I had done this sooner.

I highly suggest everyone to do this. I have already told a few members in my club, and we will be doing their Jeeps as well.

Thanks again,
Alex
 
#138 ·
This thread is great. I had dw a few weeks back and checked underneath and the track bar bolts were moving all over. Swapped them out per the thread and everything was good. A week later it is back. Not as severe and noticeable at speeds (4o mph) for example. Also it seems mostly contained to steering wheel. Seems odd but if I grasp the wheel firmly when it starts I can sometimes stop it. This is driving me nuts, any suggestions would be great
 
#140 ·
THANK YOU

Planman,

Thank you for having done this writeup here and elsewhere. I've wanted to say that for a couple of years now.
I'm sure you've helped thousands of people, assuming they took the time to actually read and absorb the information you have so clearly presented.
I've never had DW (I'm diligent about checking suspension bolts) but, having written work instructions, I sincerely appreciate a good effort like this.

Good show, Sir! :beer: Bravo!:bounce:
 
#142 ·
This write up should be a required reading for everyone looking to lift/or has recenty lifted their JK's. A lot of people go into this, (myself included), not knowing the amount of time and knowledge it takes to maintain a vehicle thats fitted with a lift/large tires. Luckily, I took it upon myself to learn what I needed, but a lot dont out of pure frustration and lack of knowledge.

So far, the only thing that has ever caused my rig to go into full on DW, was severe toe in after bending my tie rod on a tree stump.
 
#143 ·
How much play should there bee with the tie rod? I can rotate mine by twisting it up, it rotates just on the joints, but want to make sure this is ok. I've had a shimmy for a while now, and today i installed a BB teraflex kit and have dw only when i start to slow down if I'm past 50mph...
Sent from within the beaver
 
#144 ·
One issue is that all trackbar and control arm bolts should have been loosened during the BB install, and they should not have been re-torqued until the full weight of the vehicle was back on the ground at the new ride height. Otherwise, the control arm and trackbar bushings are twisted/preloaded/binding to the wrong ride height. If you did not do this correctly, go out and loosen all the control arm and trackbar bolts, vigorously rock the vehicle side-to-side and forward-and-back to unbind the bushings, and re-torque everything to spec.

Also, these will help:

PLANMAN explains Death Wobble Diagnosis and Inspection Jeep JK Wrangler Part 1 - YouTube
Part 2, PLANMAN explains Death Wobble Diagnosis and Inspection Jeep JK Wrangler - YouTube
 
#145 ·
Awesome! That answered my questions about the drag link and tire rod movement. I did not loosen the track bar before installing the lift so I'm pretty positive that is where my issue is, but in going to check the ends of everything today and make sure its all up to spec!

I also did not loosen my control arms before putting the lift on because i did not need to


Thanks planman!

Sent from within the beaver
 
#146 ·
I also did not loosen my control arms before putting the lift on because i did not need to
Whenever you change the lift height, you absolutely must loosen and then retorque all the control arm and trackbar bolts at the new ride height to avoid twisting/binding/pre-loading the bushings at the wrong ride height--leading to pre-mature failure.


Sent from my iPad using Tapatalk HD
 
#149 ·
I just put a 2.5in lift on my JKU and was getting DW pretty bad (3 times). I left the Jeep in the driveway and started researching how to fix this problem (has already read the horror stories from other people several times). Read these instructions, followed your steps to correct, and everything has gone smoothly with no problems to my Jeep.

Thanks for the fantastic write up Planman! This was extremely helpful! :beer:
 
#153 ·
Another BIG thanks to Planman!

Planman- Your time and efforts in educating the rest of us have paid off once again!

At 96k miles I was experiencing "loose" steering, as well as horiffic DW at several particular places during my daily commute.

I grabbed the kids, watched Planman's Front End Inspection videos, then headed for the garage. Using this as an educational experience to teach the kids about the steering system, we methodically checked everything and found that all four ball joints and both ends of the drag link were bad.

I installed Poly Performance ball joints and drag link, as well as replaced the 14mm track bar bolts with 9/16 grade 8 hardware.

After re-torquing everything, I headed to work. First impressions are that the steering (and front end in gereral) is noticably tighter. At 70mph, I hit the location that I experienced the worst DW and everything was tight and right!

Props-

Planman's Front End/Steering shimmy diagnosis videos are priceless!

The Poly BJ's and drag link are quality products, and fitment was perfect.

Thanks to Northridge 4x4 for the great customer sservice, quick shipping, and for having Poly's product when everyone else was out of stock :bounce:
 
#154 ·
Planman- Your time and efforts in educating the rest of us have paid off once again!

At 96k miles I was experiencing "loose" steering, as well as horiffic DW at several particular places during my daily commute.

I grabbed the kids, watched Planman's Front End Inspection videos, then headed for the garage. Using this as an educational experience to teach the kids about the steering system, we methodically checked everything and found that all four ball joints and both ends of the drag link were bad.

I installed Poly Performance ball joints and drag link, as well as replaced the 14mm track bar bolts with 9/16 grade 8 hardware.

After re-torquing everything, I headed to work. First impressions are that the steering (and front end in gereral) is noticably tighter. At 70mph, I hit the location that I experienced the worst DW and everything was tight and right!

Props-

Planman's Front End/Steering shimmy diagnosis videos are priceless!

The Poly BJ's and drag link are quality products, and fitment was perfect.

Thanks to Northridge 4x4 for the great customer sservice, quick shipping, and for having Poly's product when everyone else was out of stock :bounce:
Awesome report!

Thank you for the kudos.
 
#155 ·
Planman,

Let me toss on the kudos. After experiencing DW after 14-15 months of being DW free it hit me gain last week. I reviewed your list and watched the videos. The videos were the "pièce de résistance", watching you go through the checklist helped immensely. Grabbed my son and ran through the list using your techniques, I identified the problem within a few minutes. Tie rod ends are shot. Pretty sure as a result from the stress of the earlier bouts of DW, but regardless the parts were going to have be replaced sooner or later.

Yeah, I'm kissing your ass, but I don't care, your time and effort saved me all sorts of heartburn.

Thanks! :beer:
 
#159 ·
Planman,

Let me toss on the kudos. After experiencing DW after 14-15 months of being DW free it hit me gain last week. I reviewed your list and watched the videos. The videos were the "pièce de résistance", watching you go through the checklist helped immensely. Grabbed my son and ran through the list using your techniques, I identified the problem within a few minutes. Tie rod ends are shot. Pretty sure as a result from the stress of the earlier bouts of DW, but regardless the parts were going to have be replaced sooner or later.

Thanks! :beer:
Yep, tie rod ends were shot. Replaced them and the problem was solved.

Thanks again.
 
#156 ·
Thank you.

The feedback I've received on the videos has been great.

Even a complete newbie can gain a greater understanding of their front end and do a cursory inspection.

My friend who's JK I inspected in the videos had a 4x4 shop install a new drag link and Synergy ball joints.

My friend just needed a diagnosis, because neither the dealer or the 4x4 shop knew what to do (other than install a new steering stabilizer).
 
#158 ·
Great thanks mister Planman for Your advices and videos concerning about Death Wobble!

I purchased my second hand -07 JK Unlimited Sahara 3.8 from Germany last summer (there is no such things available in Finland but only those Italian VM 2.8 diesel engine versions I can't stand) and everything was nice until I change summertires at this spring. There was terrible death wobble whitch started like "normal" shimmy or wobble but changed quickly like car-breaking side-to-side movements. I checked things under car, tires, everything, and as my opinion nothing was wrong but steering stabilizer was leaking. Well, we have those -32C winterdays so I thought that seals are long gone, car has not been such frosed at her history in Germany! I bought new stabilizer and everything was OK for a while. At the same time I lowered tire pressure to the 1.7bar at cold and it feeled good. I make that chalk test and it looked quit good : chalk removed from whole tirewidth evenly. And suddenly those wobbles started again.

Looking Your videos and reading Your instructions I'm quite sure that my (or mine JK:s) problem is solved quite simply and quickly, just maintain her and change all her outweared parts from steering apartment like normally man should do! At first I ordered new set of shocks (I didn't yet read Your articles at that time) because I thought that if car has 127 000km behind her and has original shocks, well, they must be at their last kilometers anyway so that money is not going to emty well anyway.

I hope You undestrand my english language because I guess if I wrote in finnish language You didn't make difference if it was about some new movie in Hollywood or how they make living in Siperia ... hahaa
 
#160 ·
I had some bad DW attacks on my '08 Sahara. Ball joints felt tight, tie rod ends and drag link seemed loose (at least loose to what I'm use too). Upgrade all tie rods and drag link parts from NAPA with ones with grease fittings. Got better but still there, I finally pulled the track bar bolts, they did fit loosely. The brackets on the frame and axel were egged out some, and the bolts were loose in the track bar bushings. Replaced them with 9/16 grade 8 hardware. Much tighter. Have had no problems yet.
 
#161 ·
Help with DW needed

I've got a completely stock 2008 Unlimited Rubi and I've recently experienced what I believe is the infamous death wobble. I've gone through PlanMan's videos and write up (a big thank you for posting this info by the way) and have found a few things. I still need a little help though.

First, I replaced the frame side track bar bolt with a 9/16 grade 8. The holes were still round and the bolt does not move in the bracket. I am noticing that the bushing gives when the steering is turned side to side. I'm seeing the track bar move 1/16" to 1/8" relative to the bracket and the axle move about 1/4" relative to the frame. Again, the bolt is not moving. This is just the bushing being compressed and perhaps the track bar flexing. Does this mean I need a new bushing or is this amount of movement normal? The axle side seems to be solid, but it is also a little harder to inspect.

Second, the ball joint on the wheel side of the drag link is bad. There is about 1/8" up and down motion here. There may be some play in the other joint as well, but it's hard to tell. My question with this one is what should I replace it with. All the aftermarket drag links I've looked at are for flip mounting them and I'm not interested in this. I'd prefer the stock position, but not necessarily the stock drag link. Any recommendations for aftermarket links or should I just stick with stock?

Lastly, the steering stabilizer is shot. I understand that this is not the cause or fix, but once the cause is corrected, I'd like to replace it. Again, any recommendations here? Should I stick with the stock or go with something else.

Thanks in advance,
John
 
#163 ·
...
Second, the ball joint on the wheel side of the drag link is bad. There is about 1/8" up and down motion here. ...
John
I've replaced my BJ with Synergy's and could say the 45 mph shimmy is away. With the new BJ steering is by far better and stiffer could say.
I've replaced the track bar and re-torqued everything down there and DW becomes memory :nono-1: only.
What steering stabilizer are you using?
 
#162 ·
Thanks.

The trackbar bushing deflection is probably fine. Fix the drag link end problem first.

Both the Currie drag link and the Synergy/Poly Performance drag link can be run in the stock position (not flipped). The Synergy one is more affordable--last I looked.

If you off road, you will want to relocate the steering stabilizer to the top of the tie rod. Woods, Synergy, and others make a bolt on bracket to do this, and they sell an upgraded stabilizer with the bracket. That is what you want. However, unless you run tires that cause a drift to the right--like Toyo MTs--you do not want a gas charged stabilizer that pushes more to the left.


Sent from AutoGuide.com App
 
#165 ·
Better, but not fixed yet.

Okay, I replaced my worn out drag link joints with a new Synergy drag link. Unfortunately, the death wobble did not go away. It did get better though. Before it would start at about 40 mph, now it doesn't start until about 60 mph. I went down the list again trying to find what else is wrong, but couldn't find anything obvious like last time.
I had my son turn the wheel side to side while I'll checked things out under the front end. I still noticed a little "clunk" in the drag link but I couldn't see the cause. I could feel the same thing in the tie rod, but it was not quite as strong. The pitman arm is not loose and I don't see any play in the steering box. The tie rod ends seem okay (I do not see any vertical motion is them). I'm still seeing the track bar bushing flex (just the frame side), but the bolts tight and are not moving in the brackets, nor is there any wear inside the bushing from the bolts.
The upper and lower trailing arms seem okay. The bolts are tight, but I can't tell what sort of shape the bushings are in.
I jacked the front end up and checked the ball joints and wheel bearings. Using a pry bar, I tried moving the wheel up and down like in Planman's video. I'm not seeming much vertical motion in the ball joints, but I am seeing the wheel moving up and down and I can see the u-joint in the yoke moving up and down the same amount. There is also a slight "clunk" if you move it far enough. This is happening in both wheels. I thought the wheel bearings were bad, but when I grab the tire and try to move it, it's solid.
Any expert advice on what I should attack next?
I put a new, sacrificial steering stabilizer on and am keeping the speed down. I need to still use the Jeep to get back and forth to work, but I don't want to make things worse.
Thanks for any help or advice you have to offer.
 
#166 ·
Max,

There should not be a clunk when you use the pry bar to check for up and down play in the lower ball joints. So those are suspect.

You will need to remove the trackbar to inspect the bushings and the bracket bolt holes.

Speed dependent wobbles/vibrations that hale every time you reach a given speed are nearly all tire or wheel related. They could be out of balance, a wheel could be damaged or bent, someone could have failed to remove the stock lug retainer clips when installing aftermarket wheels or wheel spacers, a tire could be out of round, etc.


Sent from AutoGuide.com Free App
 
#167 ·
Thanks for the input Planman. I should explain that the first thing I did was to move the rear tires to the front axle to see if it was a tire issue. It made no difference.

As for the speed related issue, I should mention that I've been doing this test over the same stretch of road. It is relatively rough, but almost consistently so. It's not filled with bumps or potholes, just slightly rough if you know what I mean. The first time I experienced this problem was on this road doing about 60 mph. Over the course of a week it got progressively worse until it got to the point where it would happen at 40 mph. The old steering stabilizer was leaking oil, so I just figured that this progression was due to the stabilizer getting worse and allowing the DW to surface with less of a disturbance input. During all this time I was keeping the speed down and trying to prevent the DW from starting. It happened a total of 4 times. Each time I was able to hit the breaks almost immediately and come to a stop very quickly. I have not tested it again since putting on the new steering stabilizer as I know the problem has not gone away.

Regarding the track bar, I did remove it and inspect the bushings and brackets. Everything looked okay. I did however replace the M14 fasteners with 9/16 bolts. On the frame side I was able to use some washers with a longer bolt so that only the unthreaded shoulder is going through the bushing and bracket. I was not able to do this on the axle side though. The bolts are not moving in the brackets. The frame side bushing is getting worked quite a bit and it is compressing about 1/8" under load. I'm probably going to try replacing this bushing with the one Teraflex sells. I figure it can't hurt. Do you know if both ends of the track bar take the same bushing?

When I did that test of moving with wheels up and down using a pry bar, the yoke holding the wheel assembly did not move much at all (just a few thousandths). What I noticed moving a bit was the u-joint inside that yoke. That makes me think the wheel bearings inside that yoke are worn, but when I shake the tire up and down and side to side it feels solid. If I push hard on the pry bar I do hear a slight "clunk" sound though.
I know the ball joints are still covered under warranty, but I'm not sure about the bearings. Maybe I'll take it to them and have those joints and bearings inspected for wear. I'm reluctant to take it in though because those guys seem to be pretty clueless about DW.

As for the tires, they are worn, but I was hoping to get at least another 6 months out of them. Based on what you said though I guess I'll be looking for new tires this weekend, for the front axle at least.

Thanks again for your help. If you have any more thoughts I'd love to hear them.
John
 
#168 ·
On the holes for the track bar bolts, how much wobbling or movement is too much? I have replaced the factory bolts with the bigger ones as instructed, I did notice the hole seemed bigger and the new bolts wobble..but not much at all.

How do you know what is to much vs continue to look for additional issues?
 
#170 ·
Yes, I have watched them and they were a lot of help. Still have the death wobble unfortunately. Trackbar bolts was my first shot, being it was so cheap and easy to fix. Going to have to get some help and start the check list over again.

I was hoping to buy a lift this month, but looks like that money will go to anti death wobble parts instead.