And the winner is ... (Death Wobble Poll)

The week is up, the polls are closed, and the results are in. If I can get this to format in a somewhat legible fashion, the following are the results:

Problem . . . . . . . . . . . . . . . . . 1st # . . . 2nd # . . . 3rd # . . . Total Score

----------------------------------------------------------------------------------------

Worn Track Bar . . . . . . . . . . . . 15 . . . . . 15 . . . . . . 4 . . . . . . . . 79

Tire Balance . . . . . . . . . . . . . . .14 . . . . . 7 . . . . . . . 6 . . . . . . . . 62

Worn Tie Rod Ends . . . . . . . . . . 6 . . . . . .2 . . . . . . 12 . . . . . . . . 34

Worn Control Arm Bushings . . . 3 . . . . . .7 . . . . . . . 8 . . . . . . . . 31

Improper Caster Angle . . . . . . .4 . . . . . .2 . . . . . . . 2 . . . . . . . . 18

Incorrect Toe-In . . . . . . . . . . . . 1 . . . . . .3 . . . . . . . 2 . . . . . . . . 11

Worn Ball Joints . . . . . . . . . . . . 2 . . . . . .2 . . . . . . . 0 . . . . . . . . 10

Other . . . . . . . . . . . . . . . . . . . . 1 . . . . . .1 . . . . . . . 2 . . . . . . . . 7

So ... for whatever it's worth ... there's the collected wisdom of the Comanche Club.

I'll leave the three piolls stickied for a few more days so y'all can refer back to them if you wish, then (if possible after the poll closed) I'll unstick them so they can disappear gracefully.

This particular poll is about what people believe causes it. Do you think it's directly translatable into what fixes it? Meaning that if I had deathwobble and balancing the tires fixed it I would vote for that. Maybe we should have a poll only for those that have experienced it or directly know someone that had it and then they could say what it was that actually fixed it. I'd be curious how that compares to the first poll.

I found out what caused the DW that I had by fixing things until the problem was taken care of...? :popcorn:

I found out what caused the DW that I had by fixing things until the problem was taken care of...? :popcorn:

Did you do things one at a time? If so, what was the last thing?

This particular poll is about what people believe causes it. Do you think it's directly translatable into what fixes it? Meaning that if I had deathwobble and balancing the tires fixed it I would vote for that. Maybe we should have a poll only for those that have experienced it or directly know someone that had it and then they could say what it was that actually fixed it. I'd be curious how that compares to the first poll.

Pete, IMHO there is no question that if you eliminate the CAUSE, you eliminate the death wobble. What makes it complicated is that you can "fix" things that aren't the cause and cover up the death wobble. Yes, you "fixed" it in that you can drive down the road at 55 MPH ... but something is still lurking just under the surface.

Despite the poll results, I remain of the opinion that the root cause is almost always tire balance, and that insufficient caster angle can result in the tire balance showing up as death wobble. However, caster angle itself doesn't cause tires to shake. We now routinely run 6 to 8 degrees of positive caster. Back in the late 50s and early 60s, 1-1/2 degrees of caster was a LOT, and yet tires weren't jumping off the road as soon as you hit 50 MPH.

I don't know what real good this poll is. Ultimately, regardless of how it's worded, I think people voted for the things they have "fixed" as being the cause. So in that sense, I guess the final standings could be viewed as a probable hierarchy of what to check first if you have death wobble.

Despite the poll results, I remain of the opinion that the root cause is almost always tire balance, and that insufficient caster angle can result in the tire balance showing up as death wobble. However, caster angle itself doesn't cause tires to shake. We now routinely run 6 to 8 degrees of positive caster. Back in the late 50s and early 60s, 1-1/2 degrees of caster was a LOT, and yet tires weren't jumping off the road as soon as you hit 50 MPH.

 

I don't know what real good this poll is. Ultimately, regardless of how it's worded, I think people voted for the things they have "fixed" as being the cause. So in that sense, I guess the final standings could be viewed as a probable hierarchy of what to check first if you have death wobble.

Well...after starting to read this thread, I was already formulating a reply before finishing the read, but when I got to this...the only other thing I can now think to say is...

DITTO... :cheers:

Before coming to this site, I was a FIRM believer that DW was caused by a mechanical defect and never would have considered tire balance as a cause. After some reading here and some research in a few other places, I now agree that it is (as Eagle has said) the most probable cause in most cases.

for me tire balance was never ever an issue, it was always more a mechanical or worn out part.

i see tire balance causing all sorts of problems, and possibly when the DW happens due to the balance it causes undue stress to other parts like the trackbar and wheres it out quicker. just a guess but i don't know.

but definiatly after lifting a vehicle the most important thing is the alignment and getting the the adjustments made, and checking for worn/loose parts periodically as everyone should

I pretty much eliminated tire balance in my case, as I rotated my tires about every which way, and the end result was always the same. unless all 5 tires were all out of balance by the same amount?

I do know I have it fixed now for sure, as I just drove 800+ miles at 65mph this weekend as well as 6+ hours off road about halfway through without ever experiencing it again. Lots of pot holes and bumps on the highway as well.

Also found out the beads in my tires do not always keep them properly balanced above 55 mph, but usually when they are out of balance, the first pot hole I hit fixes them again. Methinks maybe they should have put a bit more in.

Had a new cause of it the other day...

I came down to Iowa to meet up with a friend and on the way my trackbar decided to just fall out of the bracket at 75 mph.

Luckily it happened about 1/8th mile from an exit with a hardware store right off of it, so I popped the castlenut off the steering shock and threaded it on, then limped to the store and got some new nuts. It still did it after that, but I eventually stopped and rotated the tires and it only did it once for the last 70ish miles of the trip.

I havent driven my truck all that much.. I just know on my prelude i had a real bad shimmy at about 55 to 70 with the shaking stopping pretty much at 70, and it would really shimmy bad when brakes were applied.. I got new tires and alignment and it pretty much stopped all shakes...

Had a new cause of it the other day...

 

I came down to Iowa to meet up with a friend and on the way my trackbar decided to just fall out of the bracket at 75 mph.

 

Luckily it happened about 1/8th mile from an exit with a hardware store right off of it, so I popped the castlenut off the steering shock and threaded it on, then limped to the store and got some new nuts. It still did it after that, but I eventually stopped and rotated the tires and it only did it once for the last 70ish miles of the trip.

Popped out? Was there a cotter pin in the castle nut?

I havent driven my truck all that much.. I just know on my prelude i had a real bad shimmy at about 55 to 70 with the shaking stopping pretty much at 70, and it would really shimmy bad when brakes were applied.. I got new tires and alignment and it pretty much stopped all shakes...

Shimmy is a far cry from death wobble. Death wobble is called that because when it happens, your life flashes in front of your eyes and you KNOW you're gonna die in about 2.37 seconds. Death wobble is like a demented djini has grabbed hold of the front of your truck and is doing his best to fling it forcefully off the road into the nearest ditch. Basically, if you don't wet yourself -- it isn't death wobble.

Death wobble is generally unlikely in a vehicle with independent front suspension because you don't have that big, SOLID axle rigidly connecting both wheels, both steering knuckles, and everything associated therewith. It's hard for the harmonic feedback to get a toehold when there's nothing solid through which it can transfer.

I havent driven my truck all that much.. I just know on my prelude i had a real bad shimmy at about 55 to 70 with the shaking stopping pretty much at 70, and it would really shimmy bad when brakes were applied.. I got new tires and alignment and it pretty much stopped all shakes...

Shimmy is a far cry from death wobble. Death wobble is called that because when it happens, your life flashes in front of your eyes and you KNOW you're gonna die in about 2.37 seconds. Death wobble is like a demented djini has grabbed hold of the front of your truck and is doing his best to fling it forcefully off the road into the nearest ditch. Basically, if you don't wet yourself -- it isn't death wobble.

 

Death wobble is generally unlikely in a vehicle with independent front suspension because you don't have that big, SOLID axle rigidly connecting both wheels, both steering knuckles, and everything associated therewith. It's hard for the harmonic feedback to get a toehold when there's nothing solid through which it can transfer.

Right, I was just basing my vote on what I "thought" caused DW the most...

I might have it in my truck though... I have the axles up on blocks and I can turn the wheel all the way right ( I think) and the body moves to the left.. Think Ill get any DW in a 2wd??

When mine was about 6 years old (and all stock). I had an event at 45 or 50, very repeatable. I thought the shocks were shot but that didn't help. Took it to the dealer and they replace stabilizer or track rod, I don't remember which. That fixed it. Years later an out of round tire was an issue. Replacing the track rod didn't help.

The big problem here is there is death wobble which sounds like an undamped resonant frequency response, which probably only a lucky few actually have experienced, but then there are all sorts of different events that may seem like death wobble. Hence the many different opinions.

We should simply establish a list of items to check. Obviously, any worn suspension/steering components should be replaced whether they cause an event or not. A must on the list would be tire inspection or substitution. Sometimes a simple swap front to rear can pin point a problem with the tires.

Perhaps as a community we should advocate an annual inspection of our own suspension/steering components with a DIY post. When I still went to the dealer for free state inspection, they often claimed the track rod was shot. Then I took it to a local station and not a word. So was I being taken by the dealer or the local guy didn't know what he was doing? ( I did replace it later and do the swirm test)

Notice I did not say that I experienced DW because I don't think I did. It was more trouble some then scary. However, I not lifted with heavier, larger tires, which I'm sure will amplify any wobble and put more strain on the components.

Okay, so what causes one of the front castors on a grocery cart to wobble all the time?

We should simply establish a list of items to check.

We just did. I think the result of the poll serves as a checklist. If we want to flesh it out even more, you could ask those who voted for "Other" what they had in mind.

...

Notice I did not say that I experienced DW because I don't think I did. It was more trouble some then scary. However, I not lifted with heavier, larger tires, which I'm sure will amplify any wobble and put more strain on the components.

If you aren't sure you experienced death wobble -- you didn't. My description above is not just my own. The standard response from people who have experienced the real thing is, "I peed my pants and I thought I was gonna die right there!" This will sound a lot like a used car salesman, but "trust me on this" -- there is NO mistaking death wobble for anything else. I have a slight imbalance in a front tire on the XJ right now. It kicks in at 60 MPH but I'm good up to about 58, and it goes away at 65. I can drive it at 60, but I just prefer not to feel that constant shimmy.

If it were real death wobble, the moment it set in I would have to slam on the brakes and slow down to about 15 MPH or the vehicle would -- literally -- be uncontrollable. You absolutely CANNOT drive while death wobble is going on.

Okay, so what causes one of the front castors on a grocery cart to wobble all the time?

Great, so somebody with thorough knowledge on the suspension items should do a DIY project describing suspension inspection and make it a sticky since this is an important safety issue. Eagle's recent description of how to check a track rod by holding the end and feeling for movement is a good example.

Worn suspension items need to be addressed whether they cause wobble or not. The other point I was trying to make was even the definition of DW is not clear in some owners mind even though Eagle's and other's decription is very clear to me. I quess what I'm trying to say is let's not focus so much on DW but instead to maintain safe trucks.

my experience I damn near sharted myself at 35. every bolt on my track bar mounting bracket was finger tight. Could have been caused by an out of balance tire vibrating the bolts loose.

Had a new cause of it the other day...

 

I came down to Iowa to meet up with a friend and on the way my trackbar decided to just fall out of the bracket at 75 mph.

 

Luckily it happened about 1/8th mile from an exit with a hardware store right off of it, so I popped the castlenut off the steering shock and threaded it on, then limped to the store and got some new nuts. It still did it after that, but I eventually stopped and rotated the tires and it only did it once for the last 70ish miles of the trip.

 

Popped out? Was there a cotter pin in the castle nut?

It did when the axle was put on. Evidently it rusted off enough to where it either broke or fell out. The hardware store was out of castle nuts in that size and the castle nut from the steering shock's threads were cruddy enough to where the ball in the joint would turn before it got tight, so I had to put two regular nuts on it.

Whole trip back it didn't shake once. I guess the tires that were on the blue one when I got it are going on my red one now.

hmm, on my 90 xj my wife bent the steering stabilizer shock and i took it off. at about 50 mph, you couldn't keep the cherokee on the road. period. i replaced the stabilizer shock and the problem went away. but then, i lost a piece of tire one time and the same effect: 50 and you were off of the road. then there was the time i had a tie rod end come apart... but that was on a '76 dodge short bed 4x ..... that really caused a "death wobble". and a need for some new underware. all in all, i am of the mind that there is probably more than one cause of the "death wobble".

Ditto Eagle,

No input from the driver can correct the death wobble, you just grip the wheel, apply the brakes, view you life flashing by as you say a few hail Mary's and when it's over you may have to change your pants.

There is probably never one single isolated failure that creates death wobble but a series of worn or failing parts combined with altered front end geometry and larger heavier tires that all contribute to the experience.

I was suprised that the poll showed tire balance to be such a large issue, I agree that tires and wheel offset are a great part of the equation.

In conclusion to all of this:

4x4's require 2.5 times the maintenance of 2wd vehicles.

Now take your maintenance factor and multiply by the amount of lift that you have (2.5x6" lift =15) or basically I check my truck once a month or before any long trips.

When it was a 2wd stocker I woukd check it once or twice a year.