over the last week i've been working away trying to fix a speed wobble that i get while driving at 30mph. this past winter i installed yj springs on my zuk. i didn't guy a kit but made my own brackets etc to mount them. i'm running a 24" rear goofie leaf and missing links up front. i also run steering damperless but this wobble is so bad it wouldn't help. as i flat tow it and watching in the rear view mirrir you can see the whole front end body going side to side at 30mph at it seems to settle down around 50mph.

i've made sure the tire pressure is the same all around (20psi), changed some front bushings, shimmed the front, tightened a few things i found loose and then took it into a alignment shop to check the alignment out.. the alignment shop says the caster angle and toe in is fine. they also said there no play in the steering box. they did find a very small amount of play in the king pin bearings but said the amount there wouldn't effect anything. they checked for a bad tire and found nothing there but we rotated the tires anyways. in the end i still have this wobble.

the only thing i have left to do is change my tires and rims, which i hope to get done this week. does anyone have any more suggestions on what it could be?

Sounds like it's time to buy a trailer ;)

I still haven't solved my "Death Wobble" either. :nuke:

I had the death wobble in spades whn I first did my home-made shackle reversal YJ installation. I have got 99% of the problem solved, and here is what I found.

Caster: The caster angle is critical. I know you said your was fine, but if you do a shackle reversal, you will be off by around 8 degrees, and you can feel one degree of caster. I finally ripped my axle out, and set-up a new one with 2.5" pads welded on to compensate for the shackle reversal.

Steering Stabalizers: If your rig is set up correctly, you shouldn't need one. Mine isn't of course, so my stabilzer has helped. I got my wobble tamed a whole bunch with a steering stabailer, but it didn't get rid of the wobble, until I looked at the shocks.

Shocks: This was the key for me. I didn't belive that shocks could be an issue, and I argued with scwafish about it, but finally gave in and took off my Rancho 9000's and swapped in a pair of his Bilstiens. Shazam, problem solved like magic. Once I compared the two shocks, I noticed that the Rancho's dampening was next to nothing in compression with a whole bunch in droop. The Bilstiens were STIFF in both directions. With the really long, springy YJ's, the Ranco's were allowing a harmonic condition with the front wheels to get started (actually up and down, and NOT sideways like I had expected). Once I realized this, I could see that if I pushed down on the front bumper with the Rancho's on the rig, it would actually oscillate every so slightly around its rest point while in the driveway. Out on the road, one good bump at around 30 mph and holy bouncing balls batman! I haven't got a pair of Bilstien's yet, but I have my Rancho's turned up all the way. It ruins the ride, but even without the steering stabalizer, the death wobble is gone. And I was surpirsed to find that the Bilstien's road really nice on the road.

Panhard Bar: I also made a panhard bar. I don't think it helped the death wobble much, since I confirmed that it was vertical oscillation rather than lateral. I did find that the steering is WAY better with the panhard bar, and it hasn't hurt my flex any either.

Harmonics is a wierd phenominon. Any system that is underdampened can get this going. With the much lower spring rate of the YJ's and their muchlonger length, a different shock solution may just do it for you. Hope this helps, good luck.

Toyota SA rigs are built with 1.5-2.5 degrees of positive caster (kuckle tilted toward back of rig). Most guys have reported running around 7 degrees produces a much stabler vehicle when large tires are added.

I'm at over 10 degress right now (converted my 4Runner to solid axle from IFS) and have a death wobble from 40-45 MPH. Search for death wobble in the toy section - I started two threads in there which had some *excellent* tech info posted.

I've gotten rid of death wobble both by castor and or toe adjustments...............:D

Bobaki, I thought it was keeping your hands on the wheel that did it for you :rolleyes: :D

I think it was keeping his hands off the :beer:

watch out Tuskdaddy ,want to talk about the finer points of sparkplugs and tuning.........:D