Death wobble still there.

[mvusse]

Okay, I replaced the track bar bracket, which relocated the front axle back where it belongs: centered (and got my steering wheel pointing straight ahead now as well).

 

I also replaced the track bar itself and the ps lca, since they both had problems in the hope of fixing my death wobble. Thinking it was gone, I got brave on the freeway and when I hit a bump at 75 mph, it was back. Holy crap I'm gonna die!

 

Actually, I have since learned that even though your teeth are being rattled out of your skull, you still do have steering, so I pulled into the safety zone and slammed on the brakes. As always, around 25 or 30 mph, everything straightened out, and I continued on my way home at 55 now.

 

When I got home I checked all bolts, and everything is still tight.

 

So now what? I think I'm going to replace the other lca as well, just in case. If that doesn't fix it, I'm thinking new control arm bushings, Definitely lower, maybe upper as well?

 

Any other guesses?

 

This weekend I think I'll start a thread in the projects section, and recap everything so far, and then keep it up to date. This truck is becoming more of a project every time I work on it.

[Eagle]

Normally death wobble kicks in at around 45 or 50 MPH even if you don't hit a bump. If you can roll up to 75 MPH on smooth(ish) pavement, you're winnning. Definitely replace the other LCA -- they're cheap. Then check the balance on your tires, or just rotate the rears onto the front, and see if that makes a difference. By the time a tire is spinning at 75 MPH it should have enough gyroscope effect that it takes a LOT to make it wobble.

[Geonovast]

Yeah mine's still around too. I've elimated pretty much everything except the tires. Replaced all 4 ball joints, both bearings, both shocks, drivers side U-joint, and there is no play whatsoever in the tierods or pass U-joint, which I'm gonna replace anyway this weekend if I get time. Pretty sure my tires are completely screwed from the driving around with a 2 inch toe-in for so long.

[smartazz19]

High speed DW is usually tire related. Have you had your tires balanced recently? Even if they are balanced a set of bad tires can still wobble at 75. That was happening on my 97, it had DW at 65-70. Balanced/Rotated tires and it went away..

[Wildman]

If you have been driving XXX miles before you changed the track bar and frame bracket, and bad LCA (And yes, you should had changed out both, cause that's why some one gave you both :roll: ) the tires have developed a "pattern" from the mis-alignment, and MUST be changed / rotated.

 

With the track bar problem, axle off center, you have been dog tracking down the road, and the tires should show edge wear to that effect. More in the rear tires than the front......if I got that right.

 

As simple as switching the fronts - to - rears could solve the problem, and on the other hand, the tires them selves could be bad (which was my case in my only experience with DW) or out of balance. As you pull the tires off, inspect them for cupping (bad shocks), edge wear (bad toe-in) missing wheel weight and 'reading' the tires for what could be the next repair, Or spring the bank and invest in some new tires ;)

 

This truck is becoming more of a project every time I work on it.

 

J = Just

E = Empty

E = Every

P = Pocket

 

Now you know why it's spelled JEEP, bet you wondered how that name came about :D

[BLHTAZ]

Balance is a slim possibility as most spin balancers out there are only capable of balancing up to about 60...maybe 65 MPH. Anything beyond that, your on your own.

 

DW is primarily caused by one or more of three things... Track Bar, Control Arms (UCA and/or LCA) or Tie Rod Ends. Ball joints can be a contributor, but they are not usually the primary source. If a ball joints wobbled enough to be the only cause of DW, the wheel would fall off when it happened.

 

Shocks and the steering stabilizer are not possible causes of DW. A good strong stabilizer can minimze the effects somewhat, but it will never be the cause and shocks have nothing to do with it at all.

[mvusse]

Just for clarification, 75mph was fine for 10 minutes or so. It wasn't until I hit a bump that things went wrong.

 

Also after I had replaced everything I played with the steering some, and the only thing that moved was the wheels.

 

Before the body always shimmy sideways a bit before the wheels would turn.

[chicofuentes0224]

Take your tires to be balanced if and only if they are in good condition. While they are beeing balanced ask the tech to watch and see if your wheels are bent. This was a cause of mine.

If the tires are shot get cheap new ones from Sam's, BJ's, or Wal-Mart.

I think tire balance, allignment, and your wheels being straight are huge contributers to DW. I don't care what anyone else says. It's what I did last and should have done first. It's what finally let me get on the highway with no problems.

Good luck

[BLHTAZ]

Tire & wheel issues can definitely contribute to the problem, but there would be a constant vibration at any speed if that was the direct cause in my experience. A vibe from bent wheels, bad tires, balance issues etc... will cause tie rods, track bars & control arms to go bad and therefore ultimately you end up with DW.

 

Do as Chico says and rule that out or replace as needed :cheers: .

[Eagle]

DW is primarily caused by one or more of three things... Track Bar, Control Arms (UCA and/or LCA) or Tie Rod Ends. Ball joints can be a contributor, but they are not usually the primary source. If a ball joints wobbled enough to be the only cause of DW, the wheel would fall off when it happened.

 

Shocks and the steering stabilizer are not possible causes of DW. A good strong stabilizer can minimze the effects somewhat, but it will never be the cause and shocks have nothing to do with it at all.

I beg to differ. Track bar, control arms and tie rod ends are NEVER a "cause" of death wobble. I drove around for six months with a very badly worn track bar (like more than a quarter turn of free play at the steering wheel) and never had a hint of death wobble. Same with worn tie rod ends and LCAs.

 

What causes death wobble is whatever sets a tire to "wobbling" -- usually that's poor tire balance, or it might be warped brake rotors (in which case you get DW only when braking) or a bump in the road. Loose steering components cannot "cause" death wobble, they are just less capable of damping it out once it starts.

 

However, it's also important to be sure we're really talking about "death wobble" and not just plain old, garden variety wheel shimmy. The term death wobble gets used so often on Jeep boards that many people assume ANY wobble in a tire is death wobble. Not so. Death wobble is when the shaking in one front wheel gets transmitted to the other side, that wheel also starts shaking, and the shaking is of a frequency that each wheel harmonically reinforces the shake in the opposite side until it gets so bad that you literally cannot control the vehicle. I mean exactly what I wrote -- with death wobble, you cannot control the vehicle -- you can only slam on the brakes and pray you slow down before you run off the road or hit something.

 

That's why it is called "death" wobble -- 'cause if you don't fix it, you're gonna die.

 

Anything else is just wheel shimmy. Shimmy is not a good thing, but it's limited to one wheel and is almost always caused by tire balance. You can drive with one wheel shimmying -- I've been beside cars on the highway and you can see one front wheel jumping up and down, and the driver just keeps motoring along as if nothing is wrong. That ain't death wobble.

 

The reason most balancers only spin to about 60 MPH is that 50 to 55 MPH is the magic window where balance causes shimmy. If a tire will spin up through 55 without starting to shimmy -- it's balanced. The front tires on my '88 XJ are slightly out of balance right now. I get a slight shimmy at 55 MPH. I do not get death wobble, and at 65 it's as smooth as silk. This is not peculiar to Jeeps -- 50 to 55 has been the window for shimmy for as long as I've been playing with cars, and that's about 50 years.

[chicofuentes0224]

This is not peculiar to Jeeps -- 50 to 55 has been the window for shimmy for as long as I've been playing with cars, and that's about 50 years.

_________________

 

So, considering the fact that you can hold a wrench at about the age of 2, we can correctly assume that Eagle is at least 52 years young. :D

[Eagle]

This is not peculiar to Jeeps -- 50 to 55 has been the window for shimmy for as long as I've been playing with cars, and that's about 50 years.

_________________

 

So, considering the fact that you can hold a wrench at about the age of 2, we can correctly assume that Eagle is at least 52 years young. :D

"At least" :cheers:

[brigarpeon]

DW is primarily caused by one or more of three things... Track Bar, Control Arms (UCA and/or LCA) or Tie Rod Ends. Ball joints can be a contributor, but they are not usually the primary source. If a ball joints wobbled enough to be the only cause of DW, the wheel would fall off when it happened.

 

Shocks and the steering stabilizer are not possible causes of DW. A good strong stabilizer can minimze the effects somewhat, but it will never be the cause and shocks have nothing to do with it at all.

I beg to differ. Track bar, control arms and tie rod ends are NEVER a "cause" of death wobble. I drove around for six months with a very badly worn track bar (like more than a quarter turn of free play at the steering wheel) and never had a hint of death wobble. Same with worn tie rod ends and LCAs.

 

What causes death wobble is whatever sets a tire to "wobbling" -- usually that's poor tire balance, or it might be warped brake rotors (in which case you get DW only when braking) or a bump in the road. Loose steering components cannot "cause" death wobble, they are just less capable of damping it out once it starts.

 

However, it's also important to be sure we're really talking about "death wobble" and not just plain old, garden variety wheel shimmy. The term death wobble gets used so often on Jeep boards that many people assume ANY wobble in a tire is death wobble. Not so. Death wobble is when the shaking in one front wheel gets transmitted to the other side, that wheel also starts shaking, and the shaking is of a frequency that each wheel harmonically reinforces the shake in the opposite side until it gets so bad that you literally cannot control the vehicle. I mean exactly what I wrote -- with death wobble, you cannot control the vehicle -- you can only slam on the brakes and pray you slow down before you run off the road or hit something.

 

That's why it is called "death" wobble -- 'cause if you don't fix it, you're gonna die.

 

Anything else is just wheel shimmy. Shimmy is not a good thing, but it's limited to one wheel and is almost always caused by tire balance. You can drive with one wheel shimmying -- I've been beside cars on the highway and you can see one front wheel jumping up and down, and the driver just keeps motoring along as if nothing is wrong. That ain't death wobble.

 

The reason most balancers only spin to about 60 MPH is that 50 to 55 MPH is the magic window where balance causes shimmy. If a tire will spin up through 55 without starting to shimmy -- it's balanced. The front tires on my '88 XJ are slightly out of balance right now. I get a slight shimmy at 55 MPH. I do not get death wobble, and at 65 it's as smooth as silk. This is not peculiar to Jeeps -- 50 to 55 has been the window for shimmy for as long as I've been playing with cars, and that's about 50 years.

 

Hey Eagle guess what? We agree for a change.

 

I have had the violent shaking known as death wobble begin it's harmonic journey with an axle universal joint begin the transmission. As you've stated components can only do the job of controling it be that a good or bad job.

 

I'd like to throw this out for discussion. STAMPED STEEL control arms. They are prone to flexing from the beginnig based on the part design. That being a stamped, cheap to manufacture part. Wouldn't it be probable that over a period of time the loading and unloading of the arm in everyday driving are causing the control arm to weaken? Not enough to work harden the material but enough to cause a loss in rigidity. Rather than containing the stresses and directing but allowing more flex, thereby not controlling the harmonic motion/force. This foray is leaning more towards the stock and under 3 inch lift crowd. Over 3" begins a steering geometric journey that we probably shouldn't get into at this stage. I believe tubular LCA's do a lot to fix a stock/>3 truck. I wonder what would happen if someone were to gusset or straight bar reinforce the stock steel stamped control arms?

[jaekl]

Base on the above comments, henceforth let it be known. Whenever, you have any wobble to any extreme, check, switch, or replace your tires/wheels first. Of course a regular inspection of suspension pieces should always be done. "Man the front end fell apart but it went over the cliff as smooth as butter."

May you be bless not to actually experience true death wobble.

[BLHTAZ]

I guess this will be a point of strong disagreement for me then ;) . I have repaired DW issues many times when I worked in a 4x4 shop by tightening and/or replacing track bars or control arms/bushings. I would venture and estimate of 85% of the DW that I have cured was caused by steering/suspension components. The rest were balance or other wheel/tire related issues. I only have about half the years in as Eagle, but this has been my experience :cheers: .

[Eagle]

Death wobble is complex, but a loose component cannot initiate a wobble, and that's why I don't regard them as "causing" death wobble. All you're doing when you tighten or replace such components is help the system mask the death wobble. You haven't eliminated what makes the tires wobble in the first place -- you're just applying a stronger band-aid.

 

The original WJ Grand Cherokees had a consistent problem with death wobble in the export versions -- stock. They resolved it by replacing the front springs with a different rate. That changed the harmonic, so when one of the P245/70R16 tires started bouncing, the spring's natural frequency didn't match the frequency of the bounce. No harmonic ==> no death wobble.

 

Tightening or replacing components may alleviate death wobble; I don't dispute that. What I disagree with is saying that the loose components "cause" the death wobble. The fact that I could drive around for six months with a bad track bar clearly disproves that. If the track bar could cause it, I should not have been able to make it to work in the morning.

[brigarpeon]

I guess this will be a point of strong disagreement for me then ;) . I have repaired DW issues many times when I worked in a 4x4 shop by tightening and/or replacing track bars or control arms/bushings. I would venture and estimate of 85% of the DW that I have cured was caused by steering/suspension components. The rest were balance or other wheel/tire related issues. I only have about half the years in as Eagle, but this has been my experience :cheers: .

 

I don't speak for Eagle but from the vantage that I agree. The CAUSE is there everyday from the road shock that the vehicle experiences during travel over a myriad of surfaces. What you repaired re-established control over it's ability to become harmonic. Which is good and correct.

[jaekl]

The point of joining a forum is to pool experience. I would think by now there would be a list of attack points, in order of priority. If it can't be pin pointed to one component, then it needs to be most likely/easiest/cheapest. Tires/wheels fit that one. Mine are bolted on and I carry a wrench. Swap front to back or borrow someone elses. But always look for obvious worn suspension pieces.

[BLHTAZ]

This is the primary reason that I really enjoy coming to this site. People "talk" about things... Most other sites that this conversation has been on (which is most any Jeep site), it always ends up in the lunacy of arguing on the Internet. :roll:

 

I see and understand exactly what you are saying and will not dispute that it makes complete sense. :cheers:

[Mitch]

have you had your vehicle aligned? Professionally?

[mvusse]

I have not had an alignment done, but was planning to *after* replacing suspension components. No reason to pay for it now, only to have it done again in 3 weeks.

 

Same with tires. They are not in the best of shape, but I was planning to get new ones in July (so I still have almost new tread in Badlands).

 

So my current plan is, in order:

 

-rotate tires

-press new bushing on the spare lca and install it.

-press new bushing on the just replaced lca (assuming it's still good) and -install it on the other side.

-decide whether or not to do uppers as well.

-replace shocks.

-have a wheel alignment done.

 

And, I agree with Eagle to a point. It was hitting the bump in the road that *caused* (as in initiated) the DW, but something on the vehicle was failing to do it's job of stopping it.

 

I have never had a vehicle before that could not hit a bump in the road at 75mph without starting to violently shake side to side and that shaking can only be stopped by slowing down to 25mph.

 

And even though I have never owned a Jeep before, I cannot imagine any car being allowed to be sold where that is inherent in the design.

 

Therefore, there is something broken or worn out (or out of alignment or balance). If only there was an easy way to find out exactly what the problem is, I could fix that first, and do the rest at my leisure.

 

Any problem with my plan of attack? Or the ordering?

 

What is the consensus (or personal opinions) on urethane bushings as opposed to rubber? I know they are harder and transmit vibrations more easily, but basically, would rubber work better by dampening the vibrations more, or would urethane work better by not being as flexible?

 

Personal opinions are fine, as long as it doesn't start an argument between posters. :roll:

[Eagle]

And, I agree with Eagle to a point. It was hitting the bump in the road that *caused* (as in initiated) the DW, but something on the vehicle was failing to do it's job of stopping it.

 

I have never had a vehicle before that could not hit a bump in the road at 75mph without starting to violently shake side to side and that shaking can only be stopped by slowing down to 25mph.

 

And even though I have never owned a Jeep before, I cannot imagine any car being allowed to be sold where that is inherent in the design.

Have you ever owned a vehicle with a solid axle before? Death wobble is almost impossible in a vehicle that has independent front suspension, because there isn't enough solid connection between the front wheels to set up the destructive oscillation. And you'll virtually never hear of a Jeep with stock suspension, wheels and tires having death wobble -- the WJ export versions being an exception, and the factory fixed that quickly. So it isn't a case of selling a car with a problem inherent in the design, it's a case of owners making changes without understanding the potential implications.

 

The biggest problem is bigger tires. A bigger, wider tire has a LOT more mass than the largest standard tire, which for an MJ (or XJ) was a 225/75R15. And ... the bulk of that mass is located farther out from the rotational axis than a stock tire even has material. So if the tire is slightly out of balance, that imbalance can play a much more significant role than imbalance in a stock tire would cause.

 

I know others disagree, but I remain firm in my belief that 98% of the "cause" of death wobble is tire imbalance. Unfortunately, "But I just had my tires balanced" is not a sufficient response, because many of the minimum wage dopers running the balancer at Pep Boys or Joe's Tire and Liquor store don't really know how to use it, and they certainly don't understand that for a Jeep wearing El Humongo Terrain Destroyer tires "close enough" isn't even nearly close enough.

 

What is the consensus (or personal opinions) on urethane bushings as opposed to rubber? I know they are harder and transmit vibrations more easily, but basically, would rubber work better by dampening the vibrations more, or would urethane work better by not being as flexible?

Urethane is for on-pavement performance, where you want maximum steering precision. Think about how your control arms contort when one front wheel climbs a rock and the other one drops into a hole. The control arms TWIST. The rubber bushings help allow that twist by their flexibility. Replace them with urethane, which essentially doesn't flex, and you just twist the control arms more. If you're going to be going off-road, you really should be running after-market control arms with Johnny joints or something that's designed to rotate in more than one axis.

[chicofuentes0224]

I have not had an alignment done, but was planning to *after* replacing suspension components. No reason to pay for it now, only to have it done again in 3 weeks.

 

Same with tires. They are not in the best of shape, but I was planning to get new ones in July (so I still have almost new tread in Badlands).

 

So my current plan is, in order:

 

-rotate tires

-press new bushing on the spare lca and install it.

-press new bushing on the just replaced lca (assuming it's still good) and -install it on the other side.

-decide whether or not to do uppers as well.

-replace shocks.

-have a wheel alignment done.

 

And, I agree with Eagle to a point. It was hitting the bump in the road that *caused* (as in initiated) the DW, but something on the vehicle was failing to do it's job of stopping it.

 

I have never had a vehicle before that could not hit a bump in the road at 75mph without starting to violently shake side to side and that shaking can only be stopped by slowing down to 25mph.

 

And even though I have never owned a Jeep before, I cannot imagine any car being allowed to be sold where that is inherent in the design.

 

Therefore, there is something broken or worn out (or out of alignment or balance). If only there was an easy way to find out exactly what the problem is, I could fix that first, and do the rest at my leisure.

 

Any problem with my plan of attack? Or the ordering?

 

What is the consensus (or personal opinions) on urethane bushings as opposed to rubber? I know they are harder and transmit vibrations more easily, but basically, would rubber work better by dampening the vibrations more, or would urethane work better by not being as flexible?

 

Personal opinions are fine, as long as it doesn't start an argument between posters. :roll:[/

 

Jack each wheel up one at a time. Put your head directly under each wheel. Have your kid spin it. See if it wobbles at all. Make sure the damn truck is jacked securely up so it doesn't fall flat on your face. If you see no wobble wait. When you put the suspension on, put new tires, balance em, and allign. If everyting looks tight in your steering and your wheels are not bent you should be good. In the mean time change the bushings in your arms since you're bored and use rubber. Have fun :D

BALANCE THE TIRES

[Tomahawked]

I consider death wobble any massive shaking of the wheels requiring you to nearly stop in order to correct the problem. Definately experienced it on several lifted trucks with loose steering components and worn out tires. I had one big lifted truck in particular that just wandered all over the road. Most noticable on asphault that was crowned from lots of miles of big truck traffic. Espically bad when the tires were worn to match the road. It was a white knuckle kind of ride most of the time. I finally adjusted the toe to a little under 1/4" in. It originally had about 3/4 toe out. Good reason for it to wander so bad with that much toe out originally. Miraculously the severe wandering went away. But when hitting a bump after a certian speed the wheels shook violently. So I started adjusting the toe back out until I didnt get any wobble. It put the toe settings just out a little past zero. Probably less than 1/8". Just enough to keep the tires loaded in forward motion. But still no wandering either. SO finding that happy medium wasnt so difficult and has worked on old 2wd straight axle trucks and 4wd's. Its worth the time to try. But if your tires are noticably worn on the outer edges, may not do much good. Tires were always the most obvious problem. When that didnt work the toe settings took care of everything else. I am just a nobody that has played with 4x4's all my life. So if you try it and works, great! If not be sure to tell everyone I am an idiot.

[CWLONGSHOT]

I guess this will be a point of strong disagreement for me then ;) . I have repaired DW issues many times when I worked in a 4x4 shop by tightening and/or replacing track bars or control arms/bushings. I would venture and estimate of 85% of the DW that I have cured was caused by steering/suspension components. The rest were balance or other wheel/tire related issues. I only have about half the years in as Eagle, but this has been my experience :cheers: .

 

I am in total agreement with Eagle. he is spot on with his assessments on DW. I don't say that to "gang up" on anyone, we all learn new things everyday.

 

But in reflection to your post Blhtaz, I feel your missing the point.

Your tightening/replacing of track bars DID cure the death wobbles, I am very sure. But the loose/worn track bar doesn't CAUSE the DW. A Pot hole, tire balance, worn brake rotor, something else initiated DW. It showed that potential loose/worn parts exist. You looked at a known problem area and corrected it.

 

DW is all about harmonics. Think of an infinity sign. Ideally the "point" you want is the intersection of lines or the very center. When you get DW your steering/front end is all over the infinity sign. Its almost like its never going to stop until you do. something is pushed/pulled to one side only to have something else push it back only to have it again pulled etc....

 

Here is a couple quick scenarios;

 

In a jeep with all good/new components,

Everything is fine driving down the road. Then you hit a bump the springs rebound and the shocks dampen and you continue on with little issue.

 

In a Jeep with a worn track bar,

Everything is fine driving down the road. Then you hit a bump the springs rebound and the shocks dampen and all of a sudden a violent uncontrollable shaking begins and very rapidly increases until you jamb on the brakes to stop and everything is fine. You get out look around certain you are going to see all the wheels have fallen off and you jeep is trashed. But you find nothing. You get back in and drive. As long as you don't hit any bumps or dips nothing else happens.

 

In a Jeep with a worn track bar AND out a balance tires,

Everything is normal, you accelerate down the road. Everything is fine on small town roads where the speed is lo, say 25. but as soon as you get out on an open road, BAM, about 45mph you again get the violent shaking. Sometimes its cured by a quick stab of the brake pedal, sometimes it takes a full stop. But it reappears EVERYTIME you reach about 40MPH or hit a bump/dip in the road.

 

There are MANY things that cause DW, this is merely a few of them.

 

I hope this sheds some new light of this DW topic.

 

CW