Jeep Enthusiast Forums banner

More Death Wobble.

3K views 38 replies 13 participants last post by  Graydog 
#1 ·
Just because everything loves reading more threads about the same issue. Sorry guys. First off, I am somewhat mechanically inclined, mostly self taught in the last few years (thanks in a large part to JF and a few others), but seriously lacking in tools. I've had to borrow friends' and relatives' garages/tools to do most of my installs.

Long story short, I am in need of helping pinning this down! Any advice would be very welcome.

Background: About a month ago I was driving along a nice smooth road at ~80kph when the front end started wobbling a little (bit of a shimmy). It stopped before I pulled over, scratched my head, drove home without any problems. Re-torqued all the bolts in the front end the next day, didn't notice anything loose or abnormal. Went off-roading a few times, did plenty of driving in the interim, no problems.

About a week ago, driving around 100kph (~60mph), started as small shimmy, quickly built up into full on car-shaking-apart death wobble. Limped it home (happened twice more), looked for unusual play/looseness on the ground and jacked up, nothing stood out. Unfortunately didn't have access to all the tools I needed, so I couldn't properly check everything.

The Professional Opinions:Took it into 3 different shops, two of which I trust(ed) quite a bit, one a friend recommended. In order, an alignment shop, a suspension/spring outfit and a general off-road specialty. All three shops tell me everything on the front end is perfect, no damaged parts, no abnormal play.

The first shop tells me I have a "caster wobble", due to my 2.5" lift putting castor out of spec, and recommends adjustable front LCAs to correct it. Right. (Incidentally, I did have it aligned after the lift went on around Christmas, and checked again last week. Castor is currently 5.2* L/R, 0.8* out of factory spec)

Second shop says it's definitely a tire issue. I find it disturbing my fairly new Goodyear Wrangler Silent Armours are apparently sabotaging my vehicle.

Third shop did the shortest diagnostic effort I have ever seen and told me I definitely needed a drop pitman arm. :nuts: Which they would be happy to sell me.

So that went well. :rantscream: I still have no idea what exactly the problem is, and am poorer for my trouble. I've got a day off tomorrow and arranged to use my uncle's shop, so I'm going to go over the entire front end (trackbar, CAs, etc) with a fine tooth comb. Again.

Thanks in advance for any guesses/tips/miracle cures you guys have
:cheers2:

Only relevant modifications:
-RC 2.5" lift installed myself around X-mas. Followed the instructions to a T + a few JF recommendations. Had it aligned after.
-New tires in May (265/75-16s, on stock Rubi wheels; Moabs?). Balanced, rotated regularly.
 
See less See more
#2 ·
I don't know if I'd drop the pitman arm with only 2.5 inches of lift..
Front end allignment..oh I don't know about that, think its unlikely.
Tires..if it does not do it all the time, I would not be sure its the tires.
Maybe you have loose lugnuts and your wheels are about to fall off.
 
#4 ·
Thanks for the thoughts guys.

moonshinefuel- I'm pretty much thinking along the same lines. 3 different answers from 3 different shops, none of which make a whole lot of sense.. Pretty sure my lugnuts are on good :D

Terrain Twister- Forgot to mention I had the shop I bought the tires from check that too. I'd really expect that to be more of a consistent speed related issue though, rather than randomly occurring ... resonance (?) I've got going. Thanks though.
 
#5 ·
I'd be curious to know the diagnosis procedures the shops have done so far.

Here are the first steps I do when chasing a death wobble / front end shimmy problem:

1. Do a steering test where you turn the steering wheel back and forth rapidly while watching underneath. Do it with the tires on the ground. If there is slop in any of the steering or steering related parts, you will see it.

2. Rotate the tires front to rear and see if anything changes.
 
#6 ·
I'd be curious to know the diagnosis procedures the shops have done so far.
I have a feeling it may have involved grabbing parts and shaking them, then throwing out the first idea that came to mind. They were all somewhat evasive as to what exactly they did. I'm a tad unimpressed. Unfortunately, I was unable to stick around and watch the procedure.

1. I'll give that a try first thing.

2. Did that yesterday along with re balancing the tires. No change sadly.

Thanks.
 
#7 ·
Progress so far: :brickwall.

This is driving me up the wall. Did the steering wheel test, took everything apart, inspected it all. Couldn't find anything abnormal other than possibly a little slack in the axle side track bar bushing. Didn't trust my judgment, so I had a suspension shop mechanic take a look; he tells me it's perfectly normal flex. Had the same shop go through and take apart/inspect the entire front suspension. They didn't find anything wrong whatsoever, no slack, no worn out bushing, nothing.

So. :rantscream: This is lovely. The DW is still kicking and I'm drawing a blank. Help? Anybody have any ideas?
 
#16 ·
...possibly a little slack in the axle side track bar bushing...
What exactly do you mean a little slack? There really should be no visible movement there when doing the steering test. When you say you inspected everything, did you look at the hole in the trackbar mount on the axle? These can ge wallowed out. Also, did you watch the CA bushings while doing the test?
 
#13 ·
Interesting. Shame my local Fountain Tire don't have it (where I bought the tires). I'll have to look around.

But would that really be causing death wobble? They've been riding perfectly smooth since I got them, no rumbles or pulling what so ever at any speed. Although at this point, I'll happily try anything :D

Edit: Oh wait, yes they do. One more thing for the To-Do list.
 
#14 ·
From what I have been told on here,...if your tires a "really, really" messed up they can cause an oscillation that will overpower your components abilities to compensate.

But,....keep in mind that a RFB is not magic. ALL it does is detect out of balance points in the tire vs the actual wheel....then (assuming there IS an issue with the wheel as well) they adjust the tire on the rim so that the heavy spot on the tire is aligned with a lighter spot on the wheel. This (if done) will compensate the off-balance to some degree.....then they continue on with adding normal weights and such.
If your wheel is fine...RFB wont do much for you.
This was my case today,....big ugly bias SSR's that are prolly way out of round,....but not good rims....RFB suggested no adjustments.

READ THIS: road force balancing - what questions to ask? - Toyota Tundra Forums : Tundra Solutions Forum

Its on a toyo forum,....but one of the Hunter Engineers who designed the machine specifically talks about what it can (and can't) do for 'big ol tires'. And why.
 
#18 ·
Don't be so quick to discount road force balancing. I have a 2002 TJ with a 3" Full Traction lift. the lift was on for over a year and a half ,tires had several thousand miles, BFG AT 33x10.5x15 on factory weels. The Death Wobble came out of no where!. Retorqued all suspension bolts, had the front end alignment checked, toe in at 1/8",had the tires rebalanced twice by the shop that installed them, added adjustable cam bolts front and rear, added extended control arms to get the wheel base back. Rotated tires front to back, put the spare on, nothing! No change! At 50-53 miles per hour the front end was going up and down and sideways! Picture the paint shaker at your local hardware store! I finally swapped another set of wheels and tires on and the problem went away! Called BFG to ask WTF was wrong with my tires! Took it to a BFG dealer and had the tires road force balanced, as it turns out the tires were way out of balance!
Now 80-85 mph, smooth as can be!
In my case of Death Wobble it most definitely was tire related.
 
#22 ·
VOHK, mine would start to build right around 50mph, no problems slower than that. If you held on for dear life and powered thru it, the violent shaking and oscilating would subside. When decelerating it would occur at the same speeds. First time it happened I almost crapped my drawers, it was that bad. I took up two lanes trying to whoa it down. Then I drove home very slowly. Took almost six months to figure it out, fortunately it wasn't a DD (mostly around town), so I could take my time and work thru it.
 
#23 ·
Well, rolled the heap over to a different Fountain Tire, they checked the alignment (still spot on) and road force balanced the tires free of charge. Apparently all 5 tires (including the spare) were way the heck out of balance, but are now dead on spec. So much for the 'Commercial Vehicle Centre' Fountain Tire I bought them from having a clue..

Doesn't feel like it rides any differently, but fingers crossed that fixes it. Didn't do anything funny on the ride home at least.



Lucky you. Mine is (supposed to be) my daily driver. Not working out so well at the moment. Unfortunately I don't think we have the same problem; mine doesn't seem to be speed related, and you definitely can't power through it. Shame. So much for easy solutions.:D

Thanks for all the advice guys. I'll let you know if that got rid of it. :cheers2:
 
#25 ·
And that didn't do it. It does feel like it's riding a bit more smoothly though. Thought I had it down to just a mild steering shimmy, but it went right into full on death wobble again today. Did feel a bit 'milder', but I didn't really give it time to build up.

I think I'll be resorting to 'brother Nuclear Option': replacing most of the likely suspects (bushings, etc) on general principles. This is becoming really obnoxious.
 
#26 ·
Hey guys, I am down the same road as you. I have replaced all I can, in fact the only thing still consistent on the jeep is the rims and tires. Have had road force balancing done and nothing changed. have had Toe in from +1/2" to -1/2", caster +4deg to +8deg. changed wheel back spacing, aired tires up, aired down tires. So the next thing I am doing is mounting Centramatic wheel balancers on all 4 corners. That will consistently offset any tire problems with balance. we will see.
 
#27 ·
I've replaced all 4 front control arms, nothing abnormal about them or the bushings. Waiting for a trackbar to arrive. (all stock*. aftermarket is too expensive for my needs right now). Oddly, somewhere between the taking it all apart and replacing the control arms, the DW seems to have stopped leaving just a big shimmy. Only temporary I'm guessing.

WKENDWARIOR69- Ain't it fun? I'm seriously thinking about finding someone to swap wheels and tires for a quick drive. I doubt that's it though. Had tires rotated L/R and F/B and rebalanced a couple times. Let me know if the Centramatic bit solves your problem.


*re: aftermarket stock spec parts. Not 'bend-over-please' OEM parts. :D
 
#28 ·
Ok I found an article by the Owner (used to be) of Nth Degree that explains Death Wobble pretty darn well. Well after reading it I went out and adjusted my caster to 4deg and the death wobble pretty much went away. I made a further adjustment to 3deg and it is not completely gone. So out of all the crap I went through and stuff I put on the vehicle I just did not adjust it far enough. Just as a note, from 5deg to 8deg there was no difference in ride or the death wobble being greater or softer. I am still putting on the Centramatic to all wheels help in keeping all running smooth.

Here is the link for the article http://web.archive.org/web/20070921163647/nthdegreemobility.com/catalog/faq.php?do=show&faq_id=36

Vohk: for you it sounds like you have a mild life and still running stock size tires. Even the mild lift changes the caster. Change it back to 6degs, i bet its at 7degs now.

Well now that I got this jeep running I can do the Dusy Trail next weekend. Cant wait to do some nice wheeling and fishing.

Good luck and let me know if you have any questions.
 
#29 ·
Vohk: for you it sounds like you have a mild life and still running stock size tires. Even the mild lift changes the caster. Change it back to 6degs, i bet its at 7degs now.
Actually it`s at 5.2* on both sides IIRC, according to the shop. Unfortunately I have no way to adjust it: stock control arms up front. Might have to invest in a set of cam bolts or adjustable if the track bar doesnt solve it.

Thanks for the link.
 
#30 ·
Well I would get the adjustable lower control arms. Cams would not give you the adjustablity you are looking for. Also you don't need adjustable upper arms for lifts up to 4.5". That's what I'm at now and lowers are perfect. Running stock tires I would try to get back to 6degs. But 5degs should still work. What track bar are you going for?
 
#31 ·
:brickwall:help:i have the same exact problem with my XJ, the first time it happened i nearly **** my pants, i had JUST gotten the 3 lift put on and just got done 4 wheeling, i asked my mechanic who put the lift on if it had anything to do with the lift, he said no you probably have mud jammed up in there throwing your balance off, he reached in and grabbed a handfull off mud, theres your problem he said, i go home and clean the hell of of the tires and axle and rims and anything to do with the tires, he stopped for a while and now its happening again, its clean as a whistle i have no idea whats wrong. is it dangerous? i usually just slow down to 50 and it goes away right away:dunno::help:
 
#33 ·
:brickwall:help:i have the same exact problem with my XJ, the first time it happened i nearly **** my pants,
That sounds like DW

i had i usually just slow down to 50 and it goes away right away
That does not sound quite like DW. What's generally referred to as DW shouldn't go away until you are virtually stopped. If it only happens at a certain speed and going faster/slower gets rid of it, I'd be thinking tires. If it pops up randomly, my money would be on a shimmy about to turn into full on death wobble (worn/damaged bushings/mount on the trackbar, tie rod, CAs, etc). If you're lucky you'll find a nice smoking gun that you can fix up real quick.

Well I would get the adjustable lower control arms. Cams would not give you the adjustablity you are looking for. Also you don't need adjustable upper arms for lifts up to 4.5". That's what I'm at now and lowers are perfect. Running stock tires I would try to get back to 6degs. But 5degs should still work. What track bar are you going for?
I'm just not all that keen on getting adjustable CAs and other after market stuff. My Jeep mostly sees FSRs and minor to moderate ruff terrain on the way to campsites, rather than real wheeling. It just isn't worth it, unless it's absolutely necessary to kill off the DW.

Actually not running stock tires. Close though: 265/75-16s (~32s; Rubicon stock are 31s). Considering that link you posted recommends 5* for 33s, the current spec really *shouldn't* be the problem but I'm getting close to trying it anyway.

Just thinking of a stock replacement as far as the track bar. ~70 bucks vs 150-275, depending on quality.
 
#32 ·
Well my wobble was bad enough to have my tires chirping away. Bad part was it would go straight so if there was a turn coming up I would not be able to make it until I got the wobble under control. Pretty damn scary when you got a 18wheeler on your arse and then you break check him because your trying to calm you jeep down. Not fun. So ya I would say it's dangerous or can be. The wobble should be started by one tire hitting something the other tire does not or hitting it a different times. If it's a speed related. Wobble good chance it's a balance problem. When was the last time you had tires balanced? Also road force balancing will tell you if the rims or tires are out of round.
 
#34 ·
Pretty damn scary when you got a 18wheeler on your arse and then you break check him because your trying to calm you jeep down. Not fun. So ya I would say it's dangerous or can be.
This. Happened to me on a lovely multi-lane bridge deck in the rain. Nothing like trying to get it under control with no shoulder to work with. It is most definitely dangerous and will only get worse if you don't find the problem.
 
#35 ·
Vohk- I would agree that your caster angle is not the problem. What Is you toe in at? Was your track bar messed up making you need a new one?

Your right about not finding the problem and if you don't everytime you get the wobble it could be wrecking other parts that would have still been good. Now they too are bad. No it does not happen over night but enough wobble miles on the jeep and a bad track bar now gave you bad steering stbalizer or wallowed out mounting holes.

Right your tires are closer to 32s the stock 31s. And you being at 5.2degs should work. Problem should be else where. Have you had someone turn your steering wheel (jeep running to use power steering) while your down there looking. Also two other ways to look for movement it have some one rock you jeep front end left to right over and over to get it moving. That will show loose trackbar, steering linkage. Other way have vehicle in park or in gear and push it from the back rocking it forward and backward. You don't want the parking brake on because you want the driveline to wind up and bounce back. Don't worry you do much worse off roading or leaving the stop light. Anyway that will check to make sure your control arms are not loose or moving around.
 
#37 ·
What Is you toe in at? Was your track bar messed up making you need a new one?
I can't find the printout from the alignment, but I remember it was 'right' (the value recommended by most people on JF). I want to say 1/16" on each side, but I am not absolutely certain.

No, that's just the thing. I can't find a problem. I've taken everything apart, inspected it, had a shop do the same and there just isn't anything visible. If you read back in the thread, you'll see all the steps I've been through already. I'm pretty much down to replacing parts until the problem goes away.

Have you had someone turn your steering wheel (jeep running to use power steering) while your down there looking. Also two other ways to look for movement it have some one rock you jeep front end left to right over and over to get it moving... Other way have vehicle in park or in gear and push it from the back rocking it forward and backward.
Have done the steering test, but havn't tried rocking it. Heck, I'll give that a shot this weekend.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top