Death wobble

[mosdefjeff]

Looking for some experienced input here.

After installing my Slee 4” (DIY kit…no Slee arms) lift and going to 35s, I started experiencing a small amount of death wobble around 45 mph. I put up with this for years because it was minor and despite my trucks lack of power, I could accelerate through it and be fine after 53-55.

Fast forward a couple of years to this October. Went and did slaughterhouse. After the trail, I couldn’t drive over 25 without having to stomp the brakes. Wound up towing the truck back to Golden. Shaking like I was at a Miley Cirus concert.

Everything up front is new with exception of one of the 3 tie rod ends and was replaced with the kit. I optioned for the adjustable panhard bar as well. The truck is going in for some new 3rd members with lockers and 5.29s. While it’s there I was hoping to get this figured out. I cannot see any damaged or loose components under the truck and I think I’ve concluded it’s either a bad tire or maybe a castor issue. I’ve also heard of clearance issues with stock radius arms that can cause this.

The shop will check out my tires and see if they’re alright or need balanced. Outside of that, I was considering the Delta arms and brackets or going big with Slee 6” springs and arms and replacing all my tires with 37s, since ill be geared for that.

Long winded, but any assistance would be super helpful. I’m not near the truck, but can post photos in a day or so.

Word!
J

 

[nuclearlemon]

did you do caster plates with the springs? if so, did you tack them like recommended? they could have shifted.

 

[Stuckinthe80s]

Death wobble is usually a culmination of a bunch of things working together ( in a negative way ) to give you that wobble wobble. You said everything is new, including radius arm bushings? Worn bushings and tie rod ends will almost "resonate" together and the combined effect makes for scary driving, especially if your tires need balancing. Those vibrations run through all of the steering/suspension components and it amplifies as the speed goes up. You could push through it before because you were getting past that resonant frequency. It's not really resonant frequency but it is somewhat the same principle

 

[nuclearlemon]

was it muddy or snowpacked on the trail? i recently had snow pack throw off the balance on fat bastards tires that i couldn't get above 35mph after getting down my driveway. a few days later, everything had melted off the cruiser and no issues at all.

 

[jps8460]

I’ll echo Ige, what did you do for castor correction? If nothing, that is most likely your death wobble culprit.

 

[mosdefjeff]

The castor was corrected with the plates Slee provides. I pressed in new bushings on the radius arms at time of install. Something else I’ve always noticed, though is that there’s a lip on the spring perch for the passenger side that will catch on the spring if I hit a bigger bump or come down off a rock or something. That was confirmed with Slee to be something that happens from time to time with the DIY kits. Could be directly related to castor, though. Perhaps the axle is sitting a little too far back.

The trail was snow packed, icy and wet. No mud, but my tires definitely got pretty packed with snow. I also did a lot of driving in nasty mud back in the end beginning of October, but cleared all that out and drove home from Kremmling with no issues.

The balance will be checked at the shop, tires rotated and condition of belting checked too. These are STT Pros and about 5 years old. Maybe 20k miles on them and in good shape. Need a rotation anyway, though

I suppose the remaining tie rod end and possibly something loose could be remaining.

 

[nakman]

could be as simple as a tire lost a weight- has happened to me before... when I moved that tire to the back the death wobble went away. But I don't think it's weight alone, just the thing that tipped the other stuff in the equation over the edge.

 

[Hulk]

These are STT Pros and about 5 years old. Maybe 20k miles on them and in good shape.

I've found that I need to replace the 35s on my 80 about every 5 years regardless of mileage. They don't wear perfectly even with my 4" lift even though everything is dialed in and aligned. I'm sure that's unwelcome news since tires are so $$$, but my guess is everything will be solved with new tires.

Also, I had terrible luck with STT Pros -- I would never buy these for my 80 again. They wore worse than any other tire that I've run with my 4" lift. My faves were the BFG KO2s, and I would still be running them if they had been available last spring.

 

[mosdefjeff]

I've found that I need to replace the 35s on my 80 about every 5 years regardless of mileage. They don't wear perfectly even with my 4" lift even though everything is dialed in and aligned. I'm sure that's unwelcome news since tires are so $$$, but my guess is everything will be solved with new tires.

Also, I had terrible luck with STT Pros -- I would never buy these for my 80 again. They wore worse than any other tire that I've run with my 4" lift. My faves were the BFG KO2s, and I would still be running them if they had been available last spring.

Interesting! I’ve kept my alignment hood over the years and these tires have worn really really well. I recall hearing that they’re the same as some Mickey Thompson model (carcass at least). Perhaps there was an acquisition more recently and quality went up?

Regardless I won’t run them again. Horrible on snow and a little too noisy. I’ve always liked k02s as well. It’s on the short list…perhaps shorter depending on what the shop finds.

I’ll keep this updated with findings as well.

Thanks for all the input, guys.

 

[Inukshuk]

Any wobble on my 80 has always been loose wheel bearings.

 

[mosdefjeff]

Any wobble on my 80 has always been loose wheel bearings.

Certainly a possibility. The knuckles are getting a full refresh.