LPU_911

So the wife was driving the truck today (92 in sig) and at about 40 mph she encountered some death wobble. She was going straight and not braking, but it got significantly worse when she was braking. I came and limped the truck home, confirmed it was a bad wobble, and took a peek underneath.

The grease boot thingy between the pitman arm and drag link puked out a ton of grease, aside to that everything looked normal, and the play in the steering wheel looked like it had before.

Is it likely that this joint failed and is causing this? I really need the truck on Tuesday so I'm hoping to fix this before then.

Cheers,
Tom

maybe368

There are a few things that can cause a death wobble, tie rod ends and bad front U-joints for example, but mine was caused by the bad king pins and king pin bushings and springs. See here:

https://www.dieseltruckresource.com/...4-t290373.html

...Mark

LPU_911

Yes, that is definitely a possibility that I thought of, although I sure hope not! I also forgot to mention that I had just put on my winter tires a few days ago and have not driven the truck much at all. I'm gonna try throwing my summers back on and see if that makes a difference. Could a wheel balancing issue cause these symptoms?


Mark, I hate jumping to conclusions so I really want to figure this out before I throw parts at it. How do you diagnose to make sure it is the kingpins?

maybe368

I honestly didn't, I just decided to rebuild the whole front end and found the pins to be bad. One way to do it would be to replace the cheapest and easiest first and go from there. That said, if you didn't have a wobble before you changed the tires and one after, there is a real good chance that the tires are the culprit. Especially if it only happens at a certain speed...Mark

BILTIT

Probably time to replace your drag link too.

maybe368

I was thinking about this and thought that, yes wheel imbalance causes a wobble, usually at a certain speed, then usually goes away at a faster speed (in my experience). There is a big difference between a death wobble and a tire imbalance wobble. A death wobble feels exactly like you are going to lose control, not so with imbalance wobble, again in my experience...Mark

BILTIT

They are different yes, but a wheel imbalance could be all that is needed to trigger a death wobble. The fix for a death wobble VS tire wobble/imbalance is different though.

maybe368

I think that if an imbalance wobble causes a death wobble, that by itself indicates greater problems than just tire balance. Also, the things that cause death wobble can also cause tire imbalance. It's a tapestry ...Mark

bobva

With the weight of the cummins

These wear out fast https://www.dieseltruckresource.com/...d.php?t=302761

Not a ton of money

BILTIT

See the bolded.

maybe368

Yup, I agree completely ...Mark

LPU_911

Got an update for you guys, but I am still kinda stumped!

I put my summer tires back on (I had just changed them a week ago) and guess what? No more wobble. That led me to 3 possibilities:

1. Either the winter tires/rims are out of balance (they are only 2 winters old)
2. I did not properly center one of the wheels when I put them on
3. The aftermarket lug nuts for the summer tire alloys don't properly center my stock steel rims for the winter tires. This makes the most sense to me. They are larger acorn nuts with a small mating surface compared to stock lug nuts. Do I need to go buy some new nuts?

Thanks in advance guys, really appreciate all the help!

Tom

BILTIT

Are the winter/summer tires the same size/diameter etc.?

LPU_911

No sir, The winters are stock size and stock 1st gen steel rim.

The summer tires came with the truck when I bought it last year, 17 inch ultra wheel alloys with 265s on them.

Would that cause some kind of wheel alignment issue maybe?