Death wobble
 

I've got over a 1000 miles on my AV8 since built, been on some of the crappiest roads we have here( Google "frost heave".
Last nite I was on an overpass going about 40 and hit a deep rut that ran from side to side, and it started, I had to slow down to make it stop.
I'm wondering if somethings gone wrong, or was it just the right circumstances that set it off.
I took a quick look at the suspension when I got home and nothing. I will jack it up this weekend and dig a little deeper.

Re: Death wobble
 

Check the normal stuff for any play, tie-rod ends, king pins, spindle bearings, steering box, etc. It doesn't take much play to allow it to get started.

Re: Death wobble
 

I'm testing a VW steering damper on my AV8 and it is working great. J Seery is right. It doesn't take much.

Re: Death wobble
 

I have the early style drag link with the spring loaded ends. Maybe it's worn in enough to need adjustment.

Re: Death wobble
 

I lived in Fairbanks for 22 years. On some of those roads, a car out of the showroom can develop a death wobble!

Re: Death wobble
 

I had the same problem on my 39cs. I installed a jeep steering damper,the car handles better and no death wobble.I just installed a damper on my 1912 Case,same results!

Re: Death wobble
 

Even something as simple as loose bumper bolts can cause death wobble. Check everything.

Re: Death wobble
 

It's all about harmonics.

Re: Death wobble
 

I've been installing steering dampners on the cars coming out of my shop for years. Not as a fix but because it seems to make the steering a little more comfortable. I get mine from Pete & Jakes but the VW one is the same.

Re: Death wobble
 

That would be my first guess, had a '33 many years ago that would do that on gravel roads sometimes. Well that was the best roads we had at that time. Used to call that "shimmy", death wobble was more of a crotch rocket thing...

Re: Death wobble
 

Ahh the scourge of a solid axle, don't worry it doesn't just happen with old cars and trucks trust me. I have never had a problem with my 35 pickup BUT having experienced it in a truck I used to drive for work on a freeway I added a VW damper to my pickup just for insurance , cheap and easy..

Re: Death wobble
 

Could be a slightly loose wheel bearing ,wobble triggered by a loose steering component, check all the above and wish bone rubber ball ,perch bolts . in some cases to much negative caster ,Ted

Re: Death wobble
 

I had a '96 Bronco that had a sticky right front brake caliper, so after applying
the brake, the right front brake didn't release very quickly at all, and if you ran
over the slightest bump in the road, before the right front brake quit dragging,
that Bronco went into a death wobble that about shook all your teeth out, and
was scary as hell, till you got it pulled over to the side of the road. :eek:
I replace that caliper and a couple loose tie rod ends, and that took care of it.











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Re: Death wobble
 

A lot for Ford trucks in the solid and split beam years came with steering dampers.

Re: Death wobble
 

Bumper bolt causing death wobble,now that's a new one.

Re: Death wobble
 

Trainguy, I have a 34 Ford and have the wobble, what year of Jeep did you take the steering damper from , thanks ..R

Re: Death wobble
 

Mainly on newer 4WD pickups. Bumper is part of stiffness of frame. Might not apply to this era of vehicles.
The point is: don't rule out anything that is not correct.

Re: Death wobble
 

I found a bolt lose on the steering box to frame that solved the issue ....

Re: Death wobble
 

I believe it was for a 50s cj. I got it from adealer who specialized in early jeep parts.The one I put on my Case I bought from Amazon. It was a generic stabilizer it solver the wobble and wandering problem I was having. I just drove my 39 and is a sweet handling car compared to before the siabilizer.

Re: Death wobble
 

No wishbone ball, their split, caster is about 6-1/2 to 7 degrees. The tie rod ends are new, and so are the wishbone ends.
As much as it might help, I'm hesitant to put on a stabilizer. My car is a traditional hot rod, built as if it would have been in the early to mid fifties. Something like that would be too much out of place.
Right now the newest part I have is a 56 steering box.

Re: Death wobble
 

Are you running a panhard bar?

Re: Death wobble
 

If all of your front end parts are good put a VW steering damper on it , they are easy to install. You will be glad you did.

Re: Death wobble
 

reverse eyes ? a spring relies on tension to keep the axle stable ,Henry used stiff shackles for a dampening affect .Ted

Re: Death wobble
 

No panhard bar, yes, reversed spring eyes. And the front spring/shackle bushings are the metal with rubber type.
Of course those were such a pain to put in I cheated with the rears and used the insert type.

Re: Death wobble
 

I've been fighting the death wobble for a long time...on several cars...
I 've tryin' this and tryin' that....&.. tweakin' this and tweakin' that.
Everrrrry once in a while it will happen ... always after making a turn and only when the road is a little "lumpy"....
I think I'm going to put a damper on and see if it helps....
If it does cure it ...I'm going to slap myself for waiting so long....
Actually....
I'm going to have to get on line cause I waited too long on a lot of stuff....
just sayin'

Re: Death wobble
 

Phil,You will not regret it.Phil

Re: Death wobble
 

If the tie rod end plugs are not turned in with enough pre load on the springs this can absolutely cause the wobble or shimmy you're experiencing. I have had first hand experience with this being the cause. The tie rod basically turns into a Pogo Stick.

I thread the plugs in until the springs are fully compressed, back the plugs out to the first available alignment of the cotter pin slot then back the plugs off another 360 degrees. If the steering feels too heavy you can continue to back the plugs out 180 degrees at a time to lighten the steering but if the shimmy comes back you've gone too loose on the spring pre load.

Keep in mind that any change to the plugs (either screwed in more or out less) will affect your toe setting so you will need to reset the toe after you adjust the tie rod ends. If you have an adjustable drag link that also means you will need to adjust it to get the steering wheel back to the center position.

:)

Re: Death wobble
 

A reversed eye spring can drop the shackle from say 30deg down to 10 deg were there is not tension on the spring so you get a seesaw teta/ tota affect were the axle can go side to side ,You can have a dead man link at one end that can stop that .or you shorten the spring so a jack is needed to put the shackles in .I had a bad shimmy and had backed out the control arm plugs as Dennis is describing but also found a small bit of play in the front wheel bearing I sorted those two issues and it seem to settle down .After that I got someone to wiggle the steering wheel while I looked under neath and that's when I found the rubber wish bone ball loose .It can two things working together .Ted

Re: Death wobble
 

Ralph - I've had bad death wobble on one of my rigs and it can really be scary. To find the problem I ended up grabbing the front bumper and pulled the front of the vehicle side to side while watching everything in the front end. Works better with two (or more) people. Anyway, my problem turned out to be loose U-bolts (leaf spring to axle).
Good luck.

Re: Death wobble
 

One thing is for sure something has to be loose somewhere. That is what allows the play to develop into the shake as it reaches a harmonic.

Re: Death wobble
 

I know this an old thread but the death wobble has me concerned now. It happened to me shortly after I got my 37 Ford pick up and it happened twice today. Stock frame, reverse eye spring, disk brakes. I put new shocks on the first time it happened. I have new tires on the front. The wife said she doesn't feel safe in the pickup. I think it happens when one front tire hits a hole. I think all 3 times I was going about 40 or 45 mph. What would be some of the simple things that I can check.

Re: Death wobble
 

If you've read this entire thread, you get the idea that everything has to be in spec and sufficiently tightened. Any (seemingly) little noticed or overlooked loose/worn part or poor adjustment will contribute...to the eventual harmonic setup. I start with tire pressure/balance, then wheel bearing adjustment , then on/on.
I like the 'vibration dampener' use idea, but have always thought that that was band aid, masking something that's starting to get out of spec.

I'd like to ask any who knows....CAN slightly out of round/not trued wheel rim start/contribute to death wobble . I think the answer is yes.

Re: Death wobble
 

I'm going to put a steering stabilizer on and see if it helps. It may not be traditional, but if itt stops it, who cares.

Re: Death wobble
 

Thanks for the input guys.

Re: Death wobble
 

I'm going to go out on a limb here and say I think the cause of the death wobble is the lowered springs/dropped axles. On my original cars with stock front ends, as long as all the parts are new/rebuilt and everything is tightened/aligned properly the car is fine. On the Hot Rods EVERYTHING is new, tight and lined up properly....AND....Death Wobble happens. I have a Brookville roadster( see it on my Instagram page.. 1932 Phil) on an original frame, flathead drive train with a stock uncut wishbone. The rear spring is a POSIE with several leaves removed and the front is a reverse eye POSIE. The axle is a dropped 4'' drilled Superbell. 7.50X16 tires in the rear and 6.00X16 in the front. The car has a pretty good "rubber rake" and mechanical one as well. Enough of a rake that the lube runs DOWN the torque tube to the trans when the car is on level ground. I think with a rake like that, it changes the caster and causes the front end to wobble. We have another car with split hair pins the same rake and the front end shop brought the caster in by adjusting the hairpins. Can't do that with a stock wishbone.
OK guys ....Let's hear what y'all think of my theory....

Re: Death wobble
 

First off, yes you can adjust the caster. It is done by pie-cutting the radius rods to get the angle you want.

What do I think of your theory? Thousands and thousands of hot rods with dropped axles, reversed eye springs, etc. preform great without front end wobble and lot of totally stock cars/trucks have a major problem. It requires proper front end geometry, proper components and proper fit to work properly. Front end wobble is often traced to tires, rims and loose hub bearings and so on. Hard to blame that on dropped axles!!

Any solid front axle has a tendency toward front end wobble if everything is not kept in VERY good condition. That is the reason many later model cars and trucks came with dampers installed at the factory.

Re: Death wobble
 

I agree that it shouldn't happen to a car that everything is "right" with. But, that being said, every new Jeep or other 4x4 with a solid axle comes right from the factory with a steering stabilizer. In my lifetime as a mechanic, I have had to resort to a steering stabilizer a few times and one is on my hotrod with split bones. I had everything new, alignment done and it would still do it when I hit those bridge seams that are on a diagonal.

Re: Death wobble
 

I jacked the front end up and there is just very little play in the steering wheel. I grabbed each tire at the top and bottom then side to side and and pushed and pulled on it and didn't feel any play anywhere. The ball joints feel nice and tight and the drag link is good and tight. I've got the two front tires in my truck and I'm going to drop them off tomorrow after work to have them re-balanced. Guess I'll start with the easy stuff first.

Re: Death wobble
 

If you have un-split front wish bones, make certain to check the BALL for correct tension.
I had the wobble and was at a loss to find a reason. I rechecked the ball and found that it was looser than it should be. I tightened it and that helped considerably.
Good shocks are absolutely necessary also for front end control.

Re: Death wobble
 

I just put new Monroe shocks on a few months ago. The ball on the wishbone near the center of the frame I assume you are talking about?