Death Wobble - AGAIN!

[7.3shrk]

I need help! I thought I had this problem fixed, I checked everything, and it turned out the cause of my death wobble was too much positive caster. I shimmed the front axle and it worked. Well today I am taking my daughter to school, and the truck starts shaking violently. She thinks it's fun, and I'm crapping myself. I am lost as to how this is progressively coming back. Any suggestions or ideas?

Thanks,

Nick

 

[RLDSL]

Any chance it's something simple like the tires wore unevenly and they're out of balance ?

 

[Pipeliner_86]

If your truck has a track bar like the F350's do, that is usually the cause. But if the F250's don't have track bars because of the ttb setup, there's a good chance it could be the ball joint at the pitman arm.

 

[Pipeliner_86]

Sorry, didn't see the dana 60 in your sig. It's gonna be the track bar. If the truck doesn't have a solid track bar in it, the axle shake like crazy.

This was the cause in my truck. Got the track bar set right and tight, no more death wobble.

 

[7.3shrk]

The tires are old, and it has a rigged track bar put on by a previous owner. The problem went away for a little while after I fixed the caster, so that was why I was stumped. I was taking a closed look and found some other crap that I should address - looks like the pitman arm wobbles a little left to right, and my steering stabilizers are shot. Looks like I need to dig deeper, and find out which I should fix first. (I know they all need to be fixed, but I have Christmas presents to buy soon, and can not afford to fix it all at once)

On a side note, I read on another link about adapting a saginaw set up to our trucks - does anyone know what donor trucks or vans I can look for?

 

[84TD]

I used to get the death wobble really bad around 35~40mph and I eventually found it just comes from having a combo of unbalanced tires and loose stuff in the front end. I tightened up my front end with some new bushings and tie rod ends and a new stabilizer and ****. It was gone

 

[f-two-fiddy]

I agree with Pipeliner. Most deathwobble posts I've read, have been resolved with NEW font end parts. Usually, the track bar.

 

[aaklingler]

Does the track bar need replaced? How do you properly set up a track bar?

 

[Pipeliner_86]

A track bar should be as close to parallel with the axle as possible when setting one up. The stock bar works fine for trucks without a suspension lift, but for trucks like mine that have a significant amount of lift, you will need to fab up a track bar. I used the stock bar and just fabbed the mounting points on the frame and at the spring plate the bolts on top of the spring pack on the axle.

 

[Optikalillushun]

what about the pre-load on the king pins?

 

[7.3shrk]

I am almost certain it is the tires, it seemed to increase after I pumper them up to 50 psi and they are getting old. They are BFG Mud Terrains. I probably will not buy another set of those. I know that I need to do the front end soon too. I was wondering, why does the Ford need a track bar, when my GMC does not? I am not trying to start anything here - I am just curious about why one needs it and the other does not. By the way, the GMC is a 1985 K2500 with a Dana 60 in the front.

 

[7.3shrk]

Okay, without diving way too deep - I grabbed the top and bottoms of each tire, and they wiggle about 1/4 inch in and out, (wheel bearings), tires are old, and there is a little wobble on the steering box. I guess that I should just replace all the tie rod ends for good measure, along with replacing the crappy track bar thing.

I also found out why it is puking oil out the pass side seal - vent hose is missing and the vent is plugged.

Well I have a good starting place to blow my $$$, I hope it fixes it.

 

[subway]

yea that is loose! wheel bearings might just need to be tightened, if they still look good and not pitted and the cages hold the needles fine i would tighten them up and keep running them. i would also be a little hesitant on just throwing rod ends in there unless you are ready to do the front end. if they are tight no need to blow money on them.

a note about above, you should be able to remove the stabalizer and still have NO wobble. the stabalizer can help but can also cover problems sometimes. basically the system should work fine without it.

sound like you steering box might be worn out some, how loose is the input into the box? how does the rag joint look, are the stering box bolts tight. or worst case the frame could be cracked but i doubt that.

 

[RLDSL]

If you were running a lower pressure in some large tires, it could easily have hidden the loose wheel bearings, once you tightened up the sidewalls with more pressure, you could now feel the shaking. Most likely the wheel bearings have been too loose for a very long time. Very few people actually tighten tapered roller bearings like they are supposed to be, most people had someone down the line ( including a bunch of repair manuals now in print ) tell them to tighten them down, then back them off X amount , which leaves half the vehicles on the road with loose wheel bearings.
The spec from Timkin was 8-10 ft lbs per inch of bearing diameter . Tighten them properly and you'll never loose a bearing.Run them loose and they'll eat themselves up over time.

 

[ttman4]

What is the track bar you guys talking about? Is it something that's on 4X4 &not on 2WD like mine?

Another question. on my 2WD dually, I got 4" body lift & 2 1/2" suspension lift. I built all the brackets to drop the TwinIBeams down etc etc.
Last year I found a supposed to be a 4" drop (actually it was more like 2-3" compared to my original, but they called it 4" drop) pitman arm that fits '82 thru '96 or '98 or so F series & Bronco...never got it on, but when I was dealing with local alignment shop they decided I didn't need the drop pitman. The tierods, center drag links, etc all defiantly are at more upwards angle than before.

I still kinda think it may need that drop, but not sure.

When I think things out, drivers side tierod linkage is one length(shorter) than pass. side linkage. With suspension 2 1/2" lift, when steering is turned without using drop pitman, it's nearly turning quicker than before....???? I'm trying to think it all out in my mind....any input from somebody????

When they played & supposedly got front end aligned, using eccentric kingpin bushings, got everything aligned correctly....camber, caster, toe-in etc, I've still had nothing but trouble with alignment. Been back & back & finally gave up for now.
To me one thing it acts like is not enough pos. caster....really quick turning side to side running down road. Fall into curve & it cuts really quick either direction....nearly like have to be careful & not over steer.

Also road walks too...too much for comfort.

As I think things out, the alignment shop might have been with specs alright for a rig sitting still on alignment rack, but still now right when running down road.

Any thoughts