Dana 60 kingpin death wobble

[1972RedNeck]

Had a '93 Dodge that I got from my late great uncle that I ran for a couple years until the body fell off. When I got it, it had a minor death wobble. I rebuilt the king pins and u-joints and all was well for awhile and then a hint of death wobble came back. Added a flat washer on top of each king pin spring and all was well for about 40K miles until I parted it out.

Then I swapped it under my '72 K20. From the first drive, I had a terrible death wobble around 40 MPH. Drives great at 50+.

I got another new set of kingpin bushings and springs (genuine Spicer) and swapped in. Kept the flat washers on top of the springs. Fixed my death wobble for about two months and then it started to come back ever so slightly. Added a steering stabilizer shock which fixed it for another month or so and then a hint of death wobble showed back up. Fast forward two months to now and it has a terrible death wobble.

I assume that new springs have enough tension to keep everything tight and as time goes on and they compress the death wobble comes back?

How many washers can I add before the the spring bottoms out?

What is causing the death wobble and is there anything else I can do to fix it?

Skinny tires (8R19.5) at 80 PSI. New spring bushings. TRE are near new and tight. Tires wear perfect. Truck drives absolutely perfect, other than the death wobble.

Heavier tie rod and hydraulic assist steering? (Kidding - for the most part...)

[57taskforce]

A few things come to mind here. When you swapped the dodge 60 in did you use the offset shackles to mount it? The dodge 60’s sit on a slightly narrower perch width than the GM 60’s. If you didn’t use them I wonder if there’s something there.

Also you mentioned the spring bushings being new, what kind did you use? Did you replace the actual king pins themselves in all this? Shackle hanger bushings new too? Shackle hangers themselves not worn out? (Mine were) Bolt holes in front hangers not wallered out? (Mine were) Same with shackle holes? How about your toe, where is it set? I suspect you’ve got a bigger issue than king pin issues and you are only masking the problems by focusing on just the king pins and really obvious stuff like the rod ends. Is your truck stock height? What condition are the springs and shocks in? How is your steering box, and it’s mounting holes in the frame? Any cracks around the steering box mounts? these trucks are notorious for that. Basically any loose part or combination of loose/worn parts/mounting holes can cause death wobble. Improper toe can be a big cause and wrong air pressures can even contribute. Lots of things to look over for sure. I’ll add a link to said conversion shackles.

https://www.offroaddesign.com/hd-fro...-hanger-1.html

[1972RedNeck]

Originally Posted by 57taskforce

A few things come to mind here. When you swapped the dodge 60 in did you use the offset shackles to mount it? The dodge 60’s sit on a slightly narrower perch width than the GM 60’s. If you didn’t use them I wonder if there’s something there.

Also you mentioned the spring bushings being new, what kind did you use? Did you replace the actual king pins themselves in all this? Shackle hanger bushings new too? Shackle hangers themselves not worn out? (Mine were) Bolt holes in front hangers not wallered out? (Mine were) Same with shackle holes? How about your toe, where is it set? I suspect you’ve got a bigger issue than king pin issues and you are only masking the problems by focusing on just the king pins and really obvious stuff like the rod ends. Is your truck stock height? What condition are the springs and shocks in? How is your steering box, and it’s mounting holes in the frame? Any cracks around the steering box mounts? these trucks are notorious for that. Basically any loose part or combination of loose/worn parts/mounting holes can cause death wobble. Improper toe can be a big cause and wrong air pressures can even contribute. Lots of things to look over for sure. I’ll add a link to said conversion shackles.

https://www.offroaddesign.com/hd-fro...-hanger-1.html

I used the offset poly spring bushings. Shackles poly as well. Toe is just shy of an 1/8 - drives perfect and no tire wear.

Steering box mounting is solid. No play in the box.

All the steering parts are tight and I have went over them with a fine tooth comb. Genuine spicer parts in the axle.

2” lift springs.

[jjzepplin]

I have had the Death Wobble. I put in washers on my stock springs and that fixed it. I also have a frame strengthening kit behind my steering box. My frame was not cracked but I put it in because of the lift. A fine gentlemen on this site told me about the washer fix.

[cadillac_al]

FWIW the only time I had death wobble on my Jeep was with severely flat spotted tires. I thought the plastic dash would crumble to bits. It didn't happen all the time either. Sometimes I could drive the speed limit with no issues. I only drove it a few days like that. New tires fixed it and the rest of the suspension still has high miles on it. If your tires aren't nice and new or sit around a lot I would be suspicious.

[1972RedNeck]

Originally Posted by jjzepplin

I have had the Death Wobble. I put in washers on my stock springs and that fixed it. I also have a frame strengthening kit behind my steering box. My frame was not cracked but I put it in because of the lift. A fine gentlemen on this site told me about the washer fix.

Have a link for a 68-72 frame strengthening kit?

[57taskforce]

https://www.offroaddesign.com/weld-o...gm-trucks.html
https://www.offroaddesign.com/bolt-i...wd-trucks.html
I’ve got both of these on my trucks. I’d recommend the repair plate even if it’s not cracked. Both of my 69-72 K trucks were cracked. This will help keep it from cracking if it is. The brace really helps stiffen the whole thing up.

You also might look into the king pin spring eliminators, might help you out at as well.

[bnorth]

Are you running crossover or conventional steering linkage?

[1972RedNeck]

Originally Posted by bnorth

Are you running crossover or conventional steering linkage?

Conventional

[bnorth]

Crossover may help. I had a 92 W250 that I drove for a few years and even with 36" recapped militarys on it and it never had death wobble. I can't figure out why you're eating up kingpin springs and bushings so quickly.

[57taskforce]

You might look at this thread, note what Keith Seymour says about caster. I book marked it a while back for a friend of mine. If you are indeed killing king pin springs and bushings it is peculiar.

http://67-72chevytrucks.com/vboard/s...d.php?t=738371

[1972RedNeck]

Originally Posted by bnorth

Crossover may help. I had a 92 W250 that I drove for a few years and even with 36" recapped militarys on it and it never had death wobble. I can't figure out why you're eating up kingpin springs and bushings so quickly.

Bushings always look as good as new. More spring tension seems to help.

[1972RedNeck]

Originally Posted by 57taskforce

You might look at this thread, note what Keith Seymour says about caster. I book marked it a while back for a friend of mine. If you are indeed killing king pin springs and bushings it is peculiar.

http://67-72chevytrucks.com/vboard/s...d.php?t=738371

The thing is, this truck drives perfect outside of death wobble speed. It will literally cruise down the road at 100 MPH without touching the steering wheel. It is the best driving vehicle I have ever driven, bar none - except for the stupid death wobble.

[Dieselwrencher]

Have you tried putting the front tires on the rear to make sure it isn't a belt failure in a tire or an out of round tire? Also, if you do go to cross over I've heard you can still get death wobble without a track bar. I've built trucks with and without so I've always been on the fence about them.

[1972RedNeck]

Originally Posted by Dieselwrencher

Have you tried putting the front tires on the rear to make sure it isn't a belt failure in a tire or an out of round tire? Also, if you do go to cross over I've heard you can still get death wobble without a track bar. I've built trucks with and without so I've always been on the fence about them.

Yes, I have swapped tires all around. Doesn’t make a difference. If anything, wider tires makes it worse.

[nvrenuf]

Some folks do install track bars to fight DW but there's no reason DW can't be eliminated without a track bar. I do agree with the link to Keith S post above about caster being a big player in causing or fixing DW, you can check this with an angle finder at home and make adjustments.

I run crossover with high steer on unbalanced 40's with no DW. I do not have a track bar or a stabilizer.

[57taskforce]

Originally Posted by nvrenuf

Some folks do install track bars to fight DW but there's no reason DW can't be eliminated without a track bar. I do agree with the link to Keith S post above about caster being a big player in causing or fixing DW, you can check this with an angle finder at home and make adjustments.

I run crossover with high steer on unbalanced 40's with no DW. I do not have a track bar or a stabilizer.

That was the reason I quoted that post. More Caster fixed the death wobble on my Jeep. Different animal but still similar principles.