Death wobble while flat towing

TurboTJ

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I have started to experience death wobble on occasion. I am trying to solve that problem (unsuccessfully so far) but I was wondering if anyone has experienced death wobble while flat towing. I worry that it would not be sensed in the tow vehicle and could potentially damage or destroy the tow bar and associated hardware. It would only get worse from there of course. I am reluctant to tow the vehicle until I am confident this won’t happen.

The death wobble problem itself is driving me crazy. I have rebalanced the tires, done the dry steering test, and replaced the track bar bushing. The CAs are Currie with about 40k miles on them. I have a 2 inch OME lift and 265/75-16 KO2s. At this point I don’t know what to do other than start throwing money at it with new ball joints, rod ends, etc, even though I can’t see any problem with them. BTW, the Jeep has been driven 105k miles and flat towed maybe 20k miles. What would you normally expect to replace after 125k miles like this?
 
I am not sure but the pinion to drive shaft angle is zero.
As it should be but that wouldn't cause Death Wobble if it was not. But insufficient caster angle can and an incorrect toe-in angle can encourage DW too.

I'd have those two angles checked and measured and then let us know what they are.
 
As it should be but that wouldn't cause Death Wobble if it was not. But insufficient caster angle can and an incorrect toe-in angle can encourage DW too.

I'd have those two angles checked and measured and then let us know what they are.
I will do that.

One thing I have noted is that while there is no lateral movement in the tie rod ends or other joints in a dry steering test, there is some vertical up and down movement in the joints if I use a pry bar to force them. Is that normal?
 
I will do that.

One thing I have noted is that while there is no lateral movement in the tie rod ends or other joints in a dry steering test, there is some vertical up and down movement in the joints if I use a pry bar to force them. Is that normal?
Not normal.
 
As it should be but that wouldn't cause Death Wobble if it was not. But insufficient caster angle can and an incorrect toe-in angle can encourage DW too.

I'd have those two angles checked and measured and then let us know what they are.

I measured these as best I can in my garage with a tape measure and angle finder so the accuracy may not be great. I got 8 degrees of caster. I measured the caster from the center of the bottom ball joint stud to the center of the zerk on the top of the top ball joint. The 8 degrees is slightly more than spec but if anything I would think that would inhibit rather than cause death wobble. Do you agree?

For toe-in there is 5/16 inch difference in distance between the front and rear edges of the rims. Because that is at the rim the toe-in at the 31.6 inch diameter of the tire will be about twice that number or 5/8 inch. I will try to measure that more accurately but it sounds like the toe-in is way too much. Do you agree? Would that much toe-in be likely to cause death wobble?
 
I measured these as best I can in my garage with a tape measure and angle finder so the accuracy may not be great. I got 8 degrees of caster. I measured the caster from the center of the bottom ball joint stud to the center of the zerk on the top of the top ball joint. The 8 degrees is slightly more than spec but if anything I would think that would inhibit rather than cause death wobble. Do you agree?

For toe-in there is 5/16 inch difference in distance between the front and rear edges of the rims. Because that is at the rim the toe-in at the 31.6 inch diameter of the tire will be about twice that number or 5/8 inch. I will try to measure that more accurately but it sounds like the toe-in is way too much. Do you agree? Would that much toe-in be likely to cause death wobble?

that's a ton of toe. My tires are that size and I usually go for about 5/32".

Put the angle finder on the flat spot on the axle housing next to the diff cover. Your caster should be about that number plus 12 degrees, minus 90. Example - if it reads 86°, you would indeed have 8 degrees of caster. But that's a lot of caster.
 
I measured these as best I can in my garage with a tape measure and angle finder so the accuracy may not be great. I got 8 degrees of caster. I measured the caster from the center of the bottom ball joint stud to the center of the zerk on the top of the top ball joint. The 8 degrees is slightly more than spec but if anything I would think that would inhibit rather than cause death wobble. Do you agree?

For toe-in there is 5/16 inch difference in distance between the front and rear edges of the rims. Because that is at the rim the toe-in at the 31.6 inch diameter of the tire will be about twice that number or 5/8 inch. I will try to measure that more accurately but it sounds like the toe-in is way too much. Do you agree? Would that much toe-in be likely to cause death wobble?

Update: I had the front-end aligned and there was indeed too much toe-in. The caster was actually a little over 5 degrees. I also had the tires "road force" balanced. On a short test drive I had no death wobble but we'll see over the next few days whether it is actually gone.
 
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A little over 5 degrees of caster angle is fine for your 32's. The factory spec of 7 degrees is for factory size tires and the larger the tire diameter, the less caster angle you need. Glad you got that toe-in taken care of, things should be good now.