Help with Death Shake/Wobble

[FLINT]

Hi all.

I've had my m1028 for a couple years and it has always had the occasional death wobble - and just so there isn't any confusion - when I would hit a bump just right I would get VIOLENT shaking of the truck with the steering wheel pulling side to side until I slowed down enough for it to stop.

In the past it would only happen occasionally.

I replaced the steering stabilizer and the Tie rod (garage said it was bent). And that seemed to really help it - but would still occasionally do it.
I purchased the king bin spring/bushing kit - but didn't get around to putting them in as the death shake was still pretty sporadic.

Then, this weekend, I was driving a load of wood to my dads house and not long after I pulled of the highway and onto a secondary road, I got a bad Death Shake - and then after that - the problem became chronic!! It would go into a violent spasm on practically any bump I hit - I had to keep the truck at 25mph or less and avoid bumps or it would happen every time.

So I unloaded the truck and rotated the tires and then we replaced the king pin springs and bushings with the kit I bought a year ago, and that seemed to make it feel a little tighter, but I got less than a mile down the road - and then Bam - Violent shaking again.

So, what is next???? Something clearly has happened which made the problem go from occasional to an almost constant condition.

With the front end jacked up the wheels feel pretty tight - no side to side or up and down motion noticed.

Any suggestions would be greatly appreciated - as my truck is now stuck at my dads house and I have more wood to haul soon.

Thanks!!!!

 

[rickf]

Check the frame around the steering box bolts for cracks, very common problem. Spring bushings bad can also cause it.

Rick

 

[FLINT]

cracks in the frame sound bad. I'll have to check or have my dad check.

 

[rickf]

It is a fairly common problem and there are a lot of aftermarket solutions for it out there. Not really too bad of a job if you have decent welding skills or a good welding shop. The aftermarket plates are designed to form fit and weld in the critical areas. If you do not see the cracks with the steering box on you may have to unbolt it so you can check around the bolt holes. This may not be your problem but it is something I would check anyway.

Rick

 

[engineman2]

Wow. This could not be better timing, I'm having nearly the same problem. I don't want to hijack this but after rebuilding my kingpins (drivers side bushing was in 4 pieces, passenger in 2) , installing new brake pads and a new steering damper the steering is much tighter. But when I have firewood loaded and hit the brakes the death wobble is back. Not as bad as before, but still very apparent. I have a feeling it may be my rotors but I checked in the shop and they seem fairly consistent. Flint does your death wobble happen all the time?

 

[ODdave]

Are you guys keeping your rear brakes adjusted correctly?? If not you can over work your fronts and warp them pretty quick. 14bolts are very notorious for being out of adjustment .

Also on the subject of warped rotors, remember to torque your lug nuts. Un-even torque will warp rotors too. Torque sticks or torque wrenches are a must!

 

[mudman]

35 mile an hour shimmey!!

 

[o1951]

Something is loose.
Steering box is a good guess, as is play in steering gear.
The problem with violent death shake is it will damage good parts and loosen stuff up.
I have seen steering boxes wrecked by this.
Chock rears, lock in neutral - be safe. Crawl under it while someone moves the wheel back and forth - Does steering box wiggle? linkages have play, does steering wheel turn a bit without pitman moving?

 

[FLINT]

engineman,

my death wobble happens anytime I hit a bump at any speed over 20mph.

I do not have to push the brakes to make it start - although it seems like if it starts and i push the brakes it gets worse maybe.

and mine is not a 35 mph wobble, its like a super violent convulsion - that you absolutely have to slow down to almost a stop immediately or it feels like the truck is going to fly apart - very violent - scary.

yes, and damaging other things is what i was worried about - when it started happening chronically - I had to drive the rest of the way to my dad's house, but I don't want to drive it any more until its fixed.

I'll check all of the issues associated with the steering box. That sounds like a good place to check.

 

[KaiserM109]

No experience with an M1028 or GM trucks directly, but I believe you have a Dana axle under the front and I have lots of experience with them and the “Death Wobble” which is aptly named.

Part of this is predicated on whether or not you have a track bar on the axle; all coil spring solid axle trucks and some leaf spring trucks do. We had a Ford F100 with a wobble so bad that it was dangerous and we were going to junk the truck. I had it to 3 well know frontend shops, changed all the bushings and the damper. Everything helped a little for a while, but it ripped through bushings in 1 month. Finally a mechanic in a little garage in Commerce City, CO went straight to the problem. The bolt that mounts the trackbar to the axle was loose, but you couldn’t see it or even get in to tighten it up. He welded it solid.

Advice to anyone messing with a Dana axle with a trackbar: to prevent this problem, just weld it down, you will never need to take it off. Dana should have welded it at the factory.

Good luck.

Arlyn

 

[FLINT]

is a trackbar the same thing as a sway bar? I definitely saw what I know of as a "sway bar" (or "anti-sway bar") under the truck.

 

[KaiserM109]

is a trackbar the same thing as a sway bar? I definitely saw what I know of as a "sway bar" (or "anti-sway bar") under the truck.

No. A sway bar, also called a torsion bar, is mounted to the axle by 2 (or more) bushings that let it rotate and at the ends to the body that twist the bar in torsion when one end of the axle moves up or down more than the other. I don’t recall ever seeing a sway bar on the front axle of a 4x4.

On a coil spring mounted axle there has to be something to keep it from moving around. It has trailing arms, also called radius arms, that keep it in place front-to-back. A track bar, usually mounted so that it sits nearly level, keeps the axle from moving sideways. It is mounted to one spot on the frame and to a spot on the axle. Leaf springs generally do both jobs, but some vehicles with leaf spring, particularly newer Jeeps, have a track bar to keep the springs from twisting in an extreme situation.

Guys who do their own body lifts often screw up the track bar by not dropping the frame mount. That makes it pop the axle toward the side when the axle travels up or down.

 

[ODdave]

The chevys do not have track bars

 

[southdave]

Bite the bullet and do the king pin & ball joints ...before you make your steering box junk..

 

[swinters]

Are you running stock wheels, tires and suspension? If not, what all have you done it, especially the front end. Also, look around the frame where the steering box mounts for cracks or signs of movement. The cracks were mainly on the M1009 ("Blazer") version but some guys have reported it on the various pickup versions and loose steering boxes aren't uncommon with some lifts. Also, jack up the front end and put it on stands and grab the wheel at the top and bottom and try to rock it. King pin wear and loose wheel bearings will show up doing that. Get someone to grab the tire (while still jacked up) at the front and back and rock it real hard while you look at the tie rod ends, idler, steering box, etc. for play or movement. You can also use a bar to try to move things to check for play. The problem you're having is almost for sure on the front end and these checks should find your problem. On the other hand if you've made modifications (lifted it, swamper wheels and tires, whatever) that could be part of the problem too. Sometimes a problem is there but unnoticed until stuff gets changed and then it rears its ugly head.

 

[wayne pick]

A sway bar reduces the axle flex in trucks with leaf spring front suspension, and reduces side to side movement of the axle. Some serious off roaders remove it to increase axle travel/flex. Torsion bars repace leaf and coil springs in most if not all 1988-up independent front suspension four wheel drive GM trucks, using the lower control arm as a connection point. Torsion bars and sway bars perform two completly different tasks. A track bar and a sway bar are the same in preventing side axle movement, just different geometry.

 

[rickf]

" A track bar and a sway bar are the same in preventing side axle movement, just different geometry. "

100% completely wrong! The first sentence in the paragraph above is also wrong. A sway bar reduces body roll by transferring weight from the loaded side to the unloaded side. A Track rod centers the front (and rear if live axle, coil sprung) axle.

 

[ODdave]

Also wrong, a sway bar dose NOT center either axle.

 

[rickf]

My bad! I pointed out the mistake and corrected it with the same mistake.
I meant track rod. Has been corrected. I hate migraine headaches.

 

[wayne pick]

Why do I even reply to threads here?