The dreaded Death Wobble...

[jeepin_in_az]

I have been fighting this for quite a while ~ 2 years. It only started out really bad recently though.

Taking off from a stop, going through the gears, not race style, about to hit 30-35ish and that is when it starts. Not just a little, but too the point the tires chirp, and I have no choice but to hit the breaks.

Things that have been done:

Rock Krawler long arm upgrade kit.
Replace OR Fab steering for stock steering - ball joints seem fine.
Replaced knuckles - had to for above reason
2 new tires in the front (One is brand new, just mounted and balanced, the other was my spare that never touched the ground. Gonna balance that next week, BUT this happend on older tires too.) 22 psi. each.


Items checked:
Track bar - SkyJacker trackbar, both ends are still fine, and mounting hole is not wobbled out and it is tight.
Toe-in about 1/8" in.
Ball joints look fine.
Wheel bearings look fine, no play in wheels when off the ground and shaking it.
Shocks - tried setting 1 and setting 5 - no difference (Rancho 9000's)
Steering Stabalizer...don't have one. Never have, and it really only "masks" a problem anyway.
Front driveshaft off or on - still happens.

Tomorrow I am going to put a stabalizer on just for $hits and giggles...

Any other ideas?

[Sedona Jeep School]

Mike, We just went through the whole routine with a Jeep with a 2" lift and 33x10.50's:
1. replaced cheap & sorry stock stabilizer--improvement, but no solution. Have I mentioned that the stock stabilizers on the '04's are cheap AND sorry?
2. checked track bar (no slop or noise), though the drag link has been rubbing it in right hand turns.
3. checked sway bars--loose, but no solution.
2. balanced wheels-and discovered slightly bent rim--replaced--SOLVED.

[desertfabmotors]

Mike,

Bring your tire pressure up to around 25-28psi and toe out tires 1/8" total and make sure frt. trac-bar is friggin tight

Todd


I have been fighting this for quite a while ~ 2 years. It only started out really bad recently though.

Taking off from a stop, going through the gears, not race style, about to hit 30-35ish and that is when it starts. Not just a little, but too the point the tires chirp, and I have no choice but to hit the breaks.

Things that have been done:

Rock Krawler long arm upgrade kit.
Replace OR Fab steering for stock steering - ball joints seem fine.
Replaced knuckles - had to for above reason
2 new tires in the front (One is brand new, just mounted and balanced, the other was my spare that never touched the ground. Gonna balance that next week, BUT this happend on older tires too.) 22 psi. each.


Items checked:
Track bar - SkyJacker trackbar, both ends are still fine, and mounting hole is not wobbled out and it is tight.
Toe-in about 1/8" in.
Ball joints look fine.
Wheel bearings look fine, no play in wheels when off the ground and shaking it.
Shocks - tried setting 1 and setting 5 - no difference (Rancho 9000's)
Steering Stabalizer...don't have one. Never have, and it really only "masks" a problem anyway.
Front driveshaft off or on - still happens.

Tomorrow I am going to put a stabalizer on just for $hits and giggles...

Any other ideas?

[jeepin_in_az]

Hmmm, the one wheel is brand new since it was the spare...but the other one....

I was actually thinking that too, but it has been so long since I actually went wheeling... :D


Thanks Nena!

[jeepin_in_az]

1/8" toe out? I thought it was supposed to be toe-in?

Track bar is friggin tight...it went on with an air gun, then tightened it with tourque wrench to 110 :D

I will try it tomorrow.

[SavageSun4x4]

Mike,
The ole Cowboy here has ridden in this rodeo.

DW is most often caused by looseness in the steering components however alignment can interfere. Principal offenders are: Track Bar, Caster, Tie Rod Steering Stabilizer, Tire Balance and Tire Pressures.
• Caster: Set to about 5 1/2 degrees, +/- 1/2 degree.
• Tire pressure. I run my 37 MTRs at about 20lbs.
• Toe: 1/16" toe in. I am not convinced that toe out will solve the issue.
• Steering stabilizer: “won’t run one since they only mask other problems.” Who told you that, somebody that could not afford one? Just simply NOT, true. That said it is also TRUE that it does mask problems in near stock rigs with stock sized wheel-tire combos. I ran without one for about a year with no issues. Then I started slowly getting DW. FACT is big tires and the heavy rotational loads of wheel tire combos are a path to DW. In rigs such as ours, it does not mask squat, but rather it acts as a aide to control the horizontal harmonics that initiate DW. Steering systems such as ours wear very fast and something you may want to look at is the track bar.
• Track bar: The two ends, either one or both can be the perpetrator. Most likely, it is the bushing end. Which is the most difficult to identify. This is because the bushing, either rubber or poly can degenerate without showing a strong visual or mechanical appearance.
o Rubber bushing: The rubber can internally tear and cause an over-squish state, which leads to DW. A visual or mechanical inspection may or may NOT confirm the rubber is damaged.
• Solution: Replace rubber bushing.
o Poly: Poly being less soft than rubber and not having the resiliency can deform, again initiating DW. A latter visual or mechanical inspection will usually show it to be tight and firm.
• Solution: Replace poly bushing.
• Insure your lower Track Bar mounting bolt is a TIGHT fit in both mounting holes AND in the bushing itself. A too small bolt will allow the Track Bar to begin the wobble process. If you have tightened the bolt with a heavy hand, then a visual or mechanical inspection will only show it to be tight and firm. My wheel tire combo weighs in at about 130 lbs with a 37” diameter. Looseness in the steering system will manifest itself into DW quite quickly
• Tie Rod. Easiest to check and remedy. Insure horizontal and vertical fasteners are tight to required specs.

[OlneyJeeps]

what the heck... my 2cents:

ditto on steering stabilizer recomendation (it IS a good thing).... saying you dont need a stabilizer is equal to saying you dont need shock absorbers: vibrations harmonized by flex of tires need to be dampened just like the bounce of springs (duh!)

triple check your caster setting: the lower ball joint should be noticably fowart of upper ball joint. This gives your steering a leverage advantage. Think of the advantage as being like moving the pivot point on a teeter-toter: moving it a couple of inches exponentially changes the balance.

[Lonnie]

Double ditto on checking the castor setting, mine had the same problem once I got a little too tall on the short arms. DW would occur around 45MPH +- a couple of miles and was constant at those speeds but was able to drive thru the problem most of the time. Spent lots of time and money looking at the wrong things, finally got some upper adjustable arms and pulled the axle back to a little over -3 degrees. That got rid of the problem and haven't had it come back in over 6 months. Found a good article by Yuccaman about Death Wobble check it out http://www.yuccaman.com/jeep/dw.html if that doesnt get to the site and article then go the site without the dw.html and search for the article. Good reading and lots of info about the front end of a jeep.

Lonnie

[weasel_ugs]

Setting caster fixed my death wobble.I think I set it to +5 degrees,was at +7 degrees. Don

[OlneyJeeps]

as a PS, a "quickie" (yet expensive due to increased tire wear and decreased fuel economy) relief to DW is decreasing tire pressure. Because "ideal" pressure varies with tire size/type and vehicle weight, you generally have to experiment. Generally you will need to drop beow 18psi. The decreased "bounce" / increased flex allows the tire to absorb bumps in road without turning into vibration.

just my observations from experience with my CJ and XJ

[rockwerks]

The only way to ckeck the trackbar is with all the weight OFF the tires, and the unit hubs also have to be checked OFF the rig if you can percieve any wobble even 1/100" of an inch they are bad, toe should be at 0

[jeepin_in_az]

So this morning I did 2 things.

1. Put in a new poly bushing in the trackbar on the axle end, and new bolt on the frame end. The old poly bushing looked fine, and it was tight still.

2. Made a steering stabalizer bracket and put it on.


I can now do over 35 without the violent wobble, but can tell that it is masking the wobble.

So when I get back from DC, I will have it aligned and see if that helps the issue.

Thanks for all the input from everyone.

[JamesT]

Mike,

I still think Todd, or whoever, was right. Raise the tire pressure and toe it out.

[weasel_ugs]

My death wobble occured when I hit a bump at 45 mph.Adjusting the caster fixed that problem.
Not too long ago I cracked a wheel,I installed 2000 XJ wheels on my XJ then at 55 mph I got bad wobble.Same tires just different wheels,I changed the tires and the wobble was gone.
Seems that once you lift a Jeep anything wierd can happen :confused: . Don

[FlexyXJ]

One thing EVERYONE is missing here is MIKE NEEDS NEW TIRES!!!! Mike, your tires are thrashed!!! The odd treadwear and cupping are whats making the Jeep wobble. I had a jeep in last week that was BONE STOCK suspension wise, it had the fenders cut and 31" BFG Mud's on it. It wobbled like crazy, so I checked the Alignment settings ( YOU KNOW YOU CANT MEASURE ACCURATLY OFF THE TREAD RIGHT???? :D ) all were good. I told the customer he had crappy wear on the tires and thats what was causing it. He declined to agree with me, but when he went home he swaped tires off his Wifes ranger which were 31" all terrains. He called me back and apologized. It didnt wobble at all. he got NEW tires the next day and problem solved. Mike, Get new tires. You are gonna spend so much $$$ looking AROUND the problem. If you dont believe me, Borrow a friends tires and try it. You will be surprised!!! I also dont agree with the Toe out. I set all my Jeeps @ ZERO. As for caster, get as much positive caster that you can without a driveline vibe, or a very minimal vibe. As for getting a specific # of degrees, or "setting to MFG's spec" Its not going to happen. Your Jeep is NOT stock by ANY means.


Joe
Absolute Offroad

[OlneyJeeps]

I would tend to agree and agree with Joe. Even with a tight/good steering components, crappy tires/wheels (I incurred problem with slightly bent wheel) will cause wobble. I would think if your caster is not properly set (thereby loosing mechanical advantage) and you don't have a dampner (steering stabilizer) to absorb vibration it would grow exponentially to a DW.

Good luck
StevOinAK

[jeepin_in_az]

One thing EVERYONE is missing here is MIKE NEEDS NEW TIRES!!!! Mike, your tires are thrashed!!! The odd treadwear and cupping are whats making the Jeep wobble. I had a jeep in last week that was BONE STOCK suspension wise, it had the fenders cut and 31" BFG Mud's on it. It wobbled like crazy, so I checked the Alignment settings ( YOU KNOW YOU CANT MEASURE ACCURATLY OFF THE TREAD RIGHT???? :D ) all were good. I told the customer he had crappy wear on the tires and thats what was causing it. He declined to agree with me, but when he went home he swaped tires off his Wifes ranger which were 31" all terrains. He called me back and apologized. It didnt wobble at all. he got NEW tires the next day and problem solved. Mike, Get new tires. You are gonna spend so much $$$ looking AROUND the problem. If you dont believe me, Borrow a friends tires and try it. You will be surprised!!! I also dont agree with the Toe out. I set all my Jeeps @ ZERO. As for caster, get as much positive caster that you can without a driveline vibe, or a very minimal vibe. As for getting a specific # of degrees, or "setting to MFG's spec" Its not going to happen. Your Jeep is NOT stock by ANY means.


Joe
Absolute Offroad
Joe, read the original post....I have 2 new tires on the front... :rolleyes: :D

[OlneyJeeps]

Oddly enough, bad rear wheel/tire can cause DW too! When trying to eliminate the DW on my XJ, I rotated and started replacing tires. Although the DW was nowhere near bad after replacing fronts, it was still there. It was not untill I replaced one of the rear wheels (discount informed me it had an ever so slight bend (aluminum wheel no less) ). did the shakies go away.

[danno]

Had wobble...

My fix...

1.) Static Balance the tires.

2.) Changed to a wheel that wasn't bent. (Not sure what wheels you are using, but the standard Black RockCrawler wheels than I use are notorious for bending pretty easy. Especially at the mounting surface of the wheel.)

3.) Replaced the leaky steering stabilizer. (Perhaps it does mask the problem, but if it masks the problem so that I dont have to deal with the Death Wobble, thats fine with me. If you have checked every other possible cause of the death wobble, and it still does it, perhaps it is indeed your wheels or tires. You choices are to mask the problem with a 30 dollar steering stabilizer, or to buy new wheels and tires, which is a bit more expensive. My choice would be to mask it.

I go in from time to time to have discount tire balance the wheels. One of the times they actually badly unbalanced them, and I had death wobble as soon as I left the shop. I turned around and went back immediately, and watched them say "whoops!" as they re-tested each of the wheels.

[hydrotoys]

Mine was my fault.... and this is just 31s'.

I ran the pressure too low, and a tire rotated on the rim. Took it to Discount, and had it load-balanced. Problem solved.

[YGOHOME]

I had a similar problem on a fairly stock jeep... But I had put in someones used coils and I gained about 4 inches of lift. This was with the stock control arms still. I knew I needed to get the caster adjusted because the knuckles were nearly completely verticle/straight up and down...

symptoms were extreme wobble driving over the smallest of road imperfections, outer tire edge wear, cupping, wandering, etc. all on the stock 31" tires.

took the jeep to absolute off road and asked Joe to put in some lower adjustable rockkrawler arms to correctly adjust the caster. Rotated the cupped tires to the rear. He also fixed the toe-in which I tried doing myself previously but I was way off (I was trying to measure using the molding in the tread).

Jeep drove better than new when he was done with it.

- Ben

[SavageSun4x4]

( YOU KNOW YOU CANT MEASURE ACCURATLY OFF THE TREAD RIGHT???? :D )
Joe
Absolute Offroad

Yes you can and as accurate any other method, so there! [lets hear what Joe has to say now :D ]

[YGOHOME]

well, he did tell me of one way when I was over there

spin the tire while spraying a paint strip down its center. then spin the tire again and using the edge of a srewdriver, scribe a mark as it spins. Probably common knowledge to you guys but was the first I'd heard of doing it this way.

But I think he mentioned that he measures off the knuckles. worked for me.

tread patterns wear to unevenly to measure against tread blocks, which is what I was trying to do unsucessfuly.