death wobble...how have you fixed it?

[6.9poweredscout]

my terra has some awful death wobble. i replaced EVERY STEERING PART knuckle to knuckle on the king pin 60 front. JUST added a trac bar tonight... NO DIFFERENCE!!!!! it happens at like 10 mph for no reason, no bump, or change of steering. now my pitman arm is long, and when i turn you can see the frame move a little behind the box. bolts are tight. maybe something with the long pitman arm and short high steer arms throwing off the geometery???? i'm completely at a loss...

 

[towcat]

have you vehicle chucked up on the alignment machine and have a four wheel alignment done. why? the machine should be able to read if there is a tracking problem and do a SAI. my guess is if you have done everything, you may not have enough caster on the kingpins.
do bear in mind i'm only the boss, I'm not the alignment guru. i sell the jobs that make him earn his keep

 

[jperecko]

make sure the bracket for the track bar is beefy enough and not flexing

try to match the angle of the pitman arm to the trac bar

rotate tires around from the back as once the have been worn with poor geometry, they can potentially cause problems

 

[91dirtydiesel]

have you vehicle chucked up on the alignment machine and have a four wheel alignment done. why? the machine should be able to read if there is a tracking problem and do a SAI. my guess is if you have done everything, you may not have enough caster on the kingpins.
do bear in mind i'm only the boss, I'm not the alignment guru. i sell the jobs that make him earn his keep

For the kingpins they need specital alignment bushing to adjust the camber. I used to have 1/4" washers on top of the kingpin spring under the cap with possitive results. Make sure you run a stabilizer. Makes a world of difference. Look into the springless caps and crossover steering with heim joints, works really well

 

[towcat]

For the kingpins they need specital alignment bushing to adjust the camber. I used to have 1/4" washers on top of the kingpin spring under the cap with possitive results. Make sure you run a stabilizer. Makes a world of difference. Look into the springless caps and crossover steering with heim joints, works really well

I'm "Specialty Alignment Products" #1 pitchman in the SFbay area
they do have a camber/caster kit for up to 1.5* movement for the kingpins.
Custom Alignment in mtn. view is known for their race car alignment, we're known for pickups and commercial trucks up to 18k gvw
clicky.....
http://www.spcalignment.com/compone...na+60)&year=1976+-+1998&from=USAFrom&to=USATo

 

[91dirtydiesel]

Yea a kit, supposidly napa has a kit for like 150$

 

[6.9poweredscout]

Springless king pins, cater is 6-8 degrees or so. rotated tires, over kill on trac bar.

 

[DragRag]

I had a truck that when the tires were worn to far it would get the wobble. New tires would solve it, or a rotation. More recently on a 90' cc 4x4 I have, it had a wobble at higher speeds, a new steering stabilizer cured that one. Every truck is different I find.

 

[Black dawg]

Springless king pins, cater is 6-8 degrees or so. rotated tires, over kill on trac bar.

is there enough preload on the kingpins?

 

[6.9poweredscout]

I adjusted it on the tight side....i will double check as it's been a while.

 

[Rot Box]

How long are your shackles and are they in the front or rear of the spring? I've found front shackles over about 5" hole to hole should have a support welded in so they look like this: H. It took forever to figure that one out with my brothers rig. Everything else checked out fine, but the last idea we had was welding in a support and it eliminated death wobble completely

 

[jperecko]

Springless king pins, cater is 6-8 degrees or so. rotated tires, over kill on trac bar.

If that is the case... the trac bar should be holding it in position... the only thing left for movement would be bushings... on the trac bar and the springs/shackles.

Also maybe toe-in the tires a bit?

 

[freebird01]

ive always attributed death wobble to messed up caster...:

 

[6.9poweredscout]

Rot box, I have a brace on my shackles like that.....

I used tie rod ends on the trac bar, they're tight. If I toe it out so the tires drag it goes away, but then I'm ruining my tires. I have it set toed in a little where it should be. Now the caster is where it was when I built the truck, it never had it before, just gradually came on and got worse and worse......

 

[freebird01]

i would say the tires are wearing in. i always thought caster should be around 2º and that's how I've done all the zuks I've sprung over and never had any issues.