Sinking Creek 4WD Association

Posted: **Sun Oct 24, 2010 9:44 pm**

Jeep's got some death wobble. Had it over the summer pretty bad, put in a new track bar, didn't do anything. Got the 31's balanced, all signs of death wobble went away.

Swapped axles a month ago. Got horrible wobble back from Potts (new axles, 35's). Track bar bolt at the axle had walked its way out of the bracket. Got a bigger bolt, spread the sleeve in the bushing to fit the bolt nice and tight. Cranked the fucker down and with lock-tite. Track bar bolt at axle is nice and tight. Toe-in is good.

I adjusted my drag-link to center my steering wheel, and now the wobble is set off much more frequently. On certain roads, I can pretty much set if off setting and holding the steering wheel slightly off center. If I hit pot-holes or bridge joints anything besides square on, it will want to go into full death wobble unless I slow down (sometimes to a stop).

It's not as bad as coming back from potts. The track bar should prevent the axle from shiftin back and forth, and it is definitely tight. I also got the 35's and new wheels balanced (didn't do a great job, but the un-balanced tires on new wheels were better than old wheels and 35's with airsoft BB's).

From jacking up one side of the front axle and pushing the tire in at the top and rocking it back and forth pretty good, the ball joints appear to be fine (at least on drivers side).

Only thing constant since swapping axles is tie rod and drag link (& steering box of course). My next move may be to get new TRE's, but I'm not convinced they're the problem.

Looking to resolve the issues before harlan trip.

The steering in the Jeep has also always been quite loose, I know typical for Jeeps, but regardless, it has a fairly big dead spot at center.

Posted: **Mon Oct 25, 2010 12:19 am**

Tightening the ball joint castle nut do anything? I think that you're dead spot in the center might be contributing to the wobble due to the fact that you don't have control of the wheels a few degrees on either side of center. This could allow for the wheels to move more freely and be able to induce a death wobble condition. I tightened up the worm gear in the steering box in my bronco in high school and it took alot of the slack out of the wheel and helped the steering characteristics. You might want to look into this. Also, I know you don't believe me but having so much lift on stock short arms is not helping your suspension articulation. I realize that suspension isn't a direct contributor to steering characteristics but with your control arms at such a large angle, you have essentially made your suspension super stiff. And a super stiff suspension doesn't absorb road discontinuity as efficiently (cite the onsets of your death wobble, pot holes, road gaps etc.). When your suspension needs to articulate to accommodate varying road conditions and can't/doesn't the energy has to go somewhere and I'm willing to bet that when the shock load is transferred from the road into the tires through the springs (and the springs don't dampen effectively) the residual energy is transferred into the rest of the vehicle. No other part of your vehicle is movable like the steering and so this is likely to move with the input of kinetic energy. Look at how your steering connects from an essentially static steering box to a moving axle. Death wobble is harmonic oscillation and since you say it is an occasional occurrence, this leads me to believe that you only hit certain road occurrences sometimes at the right speed and path to induce this oscillation, otherwise everytime you hit a bump you would experience death wobble. I really think that you are not going to be able to have a Jeep that rides how you want it to (stock ride) with such a heavily modified suspension. Your TJ was specifically designed for each component to operate in accordance with the other. You have replaced or changed most of the suspension yet you have left some of the stock components (mainly control arms) that were not designed to operate how you have made them do so with your changes. To get a better ride quality you must compensate for these changes by getting your angles back to a reasonable level. Think proportionate length to height. If your stock arms were x inches long and at x degrees from horizontal you need to lengthen the arms to achieve the original angle because as you know, flatter is better. As it is now, everytime your suspension compresses you are fighting against yourself and trying to move the axle forward. It only is able to move vertically however. I fully believe that this is one of your biggest issues with the ride. Death wobble is not a condition created by one single thing that can just be replaced or tightened. It is a chain reaction of events that are caused by components not acting in harmony that is accentuated by your much larger tires. It signals a general problem with the overall suspension setup and not one root cause. But, with a modified vehicle it is not always possible to fix everything. You are so meticulous and thorough with your Jeep that I think you should continue this and finish modifying the suspension how it should be and so that it may operate better. Either get long arms to decrease the angle or take some height out of the Jeep to get the short arms back into an acceptable operating range.

Posted: **Mon Oct 25, 2010 8:43 am**

I know you said they were good but have you tried changing the caster or toe in. If everything else checks out I would try adjusting these to see if it changes it.

Posted: **Mon Oct 25, 2010 8:46 am**

WTF was all that Alec

I think we talked at the tailgate how trying to move the tire really doesn't allow you to feel or see minute ball joint movements. Mine was bad and I couldn't feel it with the tire method, had to take the tire off, put a lug nut on and move it up and down with a tire iron.....it was noticeable then and took care of my issues.

Also check the bearings. I agree with Alec on checking the castle nut. And check your steering stabilizer, after going through so many bouts of violent death wobble mine had actually lost alot of fluid and would actually "bounce" when pulled rather than damp.

Posted: **Mon Oct 25, 2010 9:55 am**

Holy shit Alec

Posted: **Mon Oct 25, 2010 10:32 am**

Alec, one word, paragraphs.

Learn to use them

Posted: **Mon Oct 25, 2010 10:38 am**

BadAssEddie wrote:Tightening the ball joint castle nut do anything? I think that you're dead spot in the center might be contributing to the wobble due to the fact that you don't have control of the wheels a few degrees on either side of center. This could allow for the wheels to move more freely and be able to induce a death wobble condition.

I tightened up the worm gear in the steering box in my bronco in high school and it took alot of the slack out of the wheel and helped the steering characteristics. You might want to look into this.

Also, I know you don't believe me but having so much lift on stock short arms is not helping your suspension articulation. I realize that suspension isn't a direct contributor to steering characteristics but with your control arms at such a large angle, you have essentially made your suspension super stiff. And a super stiff suspension doesn't absorb road discontinuity as efficiently (cite the onsets of your death wobble, pot holes, road gaps etc.). When your suspension needs to articulate to accommodate varying road conditions and can't/doesn't the energy has to go somewhere and I'm willing to bet that when the shock load is transferred from the road into the tires through the springs (and the springs don't dampen effectively) the residual energy is transferred into the rest of the vehicle. No other part of your vehicle is movable like the steering and so this is likely to move with the input of kinetic energy. Look at how your steering connects from an essentially static steering box to a moving axle. Death wobble is harmonic oscillation and since you say it is an occasional occurrence, this leads me to believe that you only hit certain road occurrences sometimes at the right speed and path to induce this oscillation, otherwise everytime you hit a bump you would experience death wobble. I really think that you are not going to be able to have a Jeep that rides how you want it to (stock ride) with such a heavily modified suspension. Your TJ was specifically designed for each component to operate in accordance with the other. You have replaced or changed most of the suspension yet you have left some of the stock components (mainly control arms) that were not designed to operate how you have made them do so with your changes. To get a better ride quality you must compensate for these changes by getting your angles back to a reasonable level. Think proportionate length to height. If your stock arms were x inches long and at x degrees from horizontal you need to lengthen the arms to achieve the original angle because as you know, flatter is better. As it is now, everytime your suspension compresses you are fighting against yourself and trying to move the axle forward. It only is able to move vertically however. I fully believe that this is one of your biggest issues with the ride.

Death wobble is not a condition created by one single thing that can just be replaced or tightened. It is a chain reaction of events that are caused by components not acting in harmony that is accentuated by your much larger tires. It signals a general problem with the overall suspension setup and not one root cause. But, with a modified vehicle it is not always possible to fix everything. You are so meticulous and thorough with your Jeep that I think you should continue this and finish modifying the suspension how it should be and so that it may operate better. Either get long arms to decrease the angle or take some height out of the Jeep to get the short arms back into an acceptable operating range.

Paragraphs ftw. and not getting long arms

Plenty of lifted Jeeps handle fine with short arm lifts and have no death wobble issues. It is definitely a matter of chasing the issue from part to part, as wearing out one part puts stress on other parts, but there's certainly a root cause among the combination of issues.

Posted: **Mon Oct 25, 2010 10:46 am**

alk1174 wrote:I know you said they were good but have you tried changing the caster or toe in. If everything else checks out I would try adjusting these to see if it changes it.

I have cam bolts on the front lower arms. I have them adjusted to the neutral position, I can adjust them "out" to see if it makes a difference. I just think it will be such a minuscule difference that it won't affect a whole lot, but I will adjust them out this week.

I've checked the toe-in over and over, and it's toed in about 3/16" to 1/4" from front to rear of the tire right now. I've had it about 1/8" to 3/16" and it has not made any difference with the wobble.

Adjusting the drag link really seemed to set things off, for some reason.

Rant, I will check the ball joints the right way this week.

Before I adjusted my drag link and was just checking out the front end of the Jeep, I noticed the passenger side lower ball joint castle nut was on there, the cotter pin was through the ball joint stud, but the nut was not seated at the knuckle/C . So, I took the pin out and cranked it down till it was seated and put the cotter pin back in. For some reason, the PO must've fucked that up somehow. After tightening, the passenger side felt a lot more solid running over pot holes and the like. So, chances are the upper ball joint could be toast on the passenger side, since it carried all the load of that side of the axle.

The most interesting thing is having the same issue across two sets of axles, with only a few items remaining constant. Regardless, it's got to get fixed sometime.

Posted: **Mon Oct 25, 2010 10:56 am**

Are your draglink and trackbar parallel? When you adjusted you draglink i think you might have made it so when you hit bumps they are even farther out of alignment than before. I know you left most everything the same as your setup from before but didn't you also lift the front another inch with spacers?

Posted: **Mon Oct 25, 2010 11:25 am**

97JEEPTJ wrote:Paragraphs ftw. and not getting long arms Plenty of lifted Jeeps handle fine with short arm lifts and have no death wobble issues. It is definitely a matter of chasing the issue from part to part, as wearing out one part puts stress on other parts, but there's certainly a root cause among the combination of issues.

Have you driven these Jeeps? Do they have a compatible amount of lift with sloppy steering? Do you have a qualitative comparison between them? Do the owners drive them as wild as you do and have the same expectations? I do not think so. Your argument is weak and flawed. I made a precise case for my side, you did not. You have an inferior (strictly speaking, not as an insult) suspension setup that is a large contributor to issues. Its not a fact of what others have done or not, it has to deal with the fact that what you have now is not ideal as it could be. I'm not saying you have to get long arms, I'm saying that you have to give credence to what I am saying. Otherwise its silly. Why is death wobble a very seldom issue with stock vehicles? Because it has to deal with the fact of people modifying things and then you throw components out of whack and cause issues like you have. Denial of this is an ignorant thought process.

You cannot make such definitive statements based upon seed of the pants impulses. You talk as if you are using scientific fact, when in fact you are filtering out what you want to hear. Don't ask for help if you are just going to brush aside everything with no corroborating evidence. You can mock my paragraphs or lack thereof all you want, but it just accentuates your selective hearing.

I believe that you just want there to be some illusive bolt or TRE that is the root cause of all your issues because its easy and follows your mindset of straightforward simple application of solutions to fix a 1 dimensional problem. But as Ary put it on July 27 in a previous death wobble thread, "I generally believe death wobble is a combination of poor alignment and worn out parts. Tight fresh parts can usually overcome poor alignment and a good alignment can often overcome worn out parts, but in conjunction, well, you're fucked". To my knowledge you still havent gotten your Jeep aligned and the last time we talked you were against it for some reason because you feel that you are more precise than a laser. lol. Fixing your parts might work in resolving your issue by masking or overriding the impulse to wobble, but you will be placing these new parts and all old existing parts under greater stress than what they were designed for (stock suspension characteristics and light offroad use), you will decrease there life span and wear out components much quicker (esp if you continue to DD your Jeep). I will bet substantial amounts of currency that you will have a reoccurring death wobble issue for as long as you have this Jeep in its current from.

And Fuck yall. I got on a roll and kept typing. I shall employ the use of paragraphs from now on.

Posted: **Mon Oct 25, 2010 11:27 am**

97JEEPTJ wrote:The most interesting thing is having the same issue across two sets of axles, with only a few items remaining constant. Regardless, it's got to get fixed sometime.

I rest my mother fucking case.

Posted: **Mon Oct 25, 2010 11:33 am**

Posted: **Mon Oct 25, 2010 11:40 am**

Jake, the lower balljoint castle nut only keeps the knuckle from falling out if you were to get airborn. The weight of the vehicle should keep it well compressed.

Please post a clear concise list of the components that the two scenarios have in common.

Posted: **Mon Oct 25, 2010 11:41 am**

All that fancy writing and you put "lol" in there.

Fawk.

Posted: **Mon Oct 25, 2010 12:04 pm**

I like how he included the date of Ary's quote. Nice touch.

Sinking Creek 4WD Association

Death Wobble

Death Wobble