The death wobble has happened to me at least four times, twice on the drivers side front and twice on the drivers side rear.

I have raised the front with D25's, replaced the ball joints and have LL's on all the tie rods and track bar. The shocks are 9000X's.

I have 3.8-4 degree's positive caster after the D25's.

Each time that I had the death wobble it was at speeds between 45-70 and it was induced when I hit a pothole or other good size irregularity in the pavement.

I saw this as a failure of the shock to control the unsprung weight; and you have to admit, the front and rear axles are heavy as hell.

I had been running the 9000X's on 5 front 3 rear and cranked them up to 7 front and 5 rear. I have not had the death wobble re-occur.

I read many lengthy threads on TDR and just don't agree with the caster causing the wobble.

Your thoughts?

 

I fought this on my 1994. I think it sounds like the tracking arm. I went through 4 in less than a year. The last one snapped in two so I got a good napa one with a lifetime warranty. They suck a lot of Edit on these trucks. I have also been told that the control bushings suck on the 2001s. When my control arm bushings went out, mine had no such symptoms but it wobbled like crazy if the tracking bar went out. I would look at both.

 

go for a DT profab track bar. A little money, but it is well worth it. It will last the longest out of all of the replacements.

 

what kind of tires do you have

 

The tires listed in my sig...

 

From doing suspension work on heavily modified 4wd's, insufficient caster is a leading cause of allowing death wobble to occur.

However, the fact that you mentioned the REAR wheel doing that is NOT death wobble. death wobble is the front wheels oscillating VIOLENTLY side to side...i.e. break your fingers in the steering wheel violent.

What you had does sound like a lack of shock control over the axle movements... and you're finding that Rancho's are a low quality shock.

 

Then I have have not experienced the death wobble, what I experienced was a violent, up and down oscillation that probably would have broken the mirrors off the truck. It was so bad each time, I stood on the brakes until I was below about 25 mph.

 

Definitely sounds like a suspension resonance. The increased shock stiffness fixing the problem supports that.

As Eskimo said, the death wobble is just that a wobble. Anyone with a very old tractor with loose steering will know exactly how it looks. The tires steer from side to side uncontrolibly, also a resonance, not vertically in the spring plane, but in the steering system. Two different problems.

 

we'll make a new term... "Death hop" to describe yours...

Never experienced that, is it an extreme example of what can happen on a washboard road?

 

I esperienced death wobble on my dodge once when running 36 TSL swampers at 30 psi. Kicked them back down to 20 and all was good. I also used to experience DW on my 4X rig (older chevy with d60s and 40" TSLs) and air pressure has alot to do with that too along with your shimmy shock and Kingpin wear. Might be thing to think about. I run my 40s at 20 psi front and 16 rear

 

Eskimo, yes that would be the same sensation except it occured at only one wheel.

 

I read a article that stated the tow in and out changes as the truck is moved up and down, the reason was because of the steering angles was not good. There was also a conversion list to change over to a hd system that had better angles on some year models. Just a idea Jim

 

My thought is that the death wobble is definitely caused by caster, but it's compounded by movement in the track bar and sector shaft.

Every time I get it I tighten up the steering box and reset the caster angle. 3.8 to 4 degrees is probably way too much, optimum is 3.2 L, 3.5 R, .3 cross caster. The proper way to obtain the right spec is to use cams in the upper ball joint to get the cross caster and camber, the swing it in with the alignment cams on the lower control arms.

Works every time.