Help diagnosing front wobble?

[gmcjimmy4x4]

Ive recently had a inconsistent problem with the hole truck wobbling side to side when i hit a pothole or bump just right. It doesnt do it everytime, but scares the hell out of you whem it does. It seems to happen about 20-30mph and wobbles untill you come to a complete stop. When you take off again, its gone. I have noticed also that the truck has not been driving a crisp as it always has before. It seems to lean and bounce more then usual and may lean a little to one side when looking straight from the front. It has 8" procomp springs on the front. Could this just be the springs wearing in? Also, you really dont feel it very much in steering wheel. Mostly just the body rolling side to side.

 

[throttleissues]

That's the infamous Death Wobble! You'll find LOTS of info about the possibilities by searching that or just DW. It's generally caused by something loose in the frontend. Could be ball joints (or king pins), TREs, shackle bushings, or maybe the springs are allowing it to flex sideways too much. Some things are spcific to the axle you're running and the steering setup. Do you have crossover steering? Do you run a steering stabilizer? All pertinnent stuff you'll find out about.

 

[gmcjimmy4x4]

The Steering is mostly stock. I have installed a 4" steering arm and drop pitman arm. It has a single steering stabilizer. Just replaced the connecting rod after it suddenly was loose after the first incident. Thought i had fixed it but guess not. Maybe it was a coincident. What are tre's?

 

[BlazerBud]

tie rod ends.

The problem with the lifted truck and non crossover steering is that feedback from the road can jolt or move the suspsension or try to turn the tires without the driver having an indication about this. Basically there is inherent play in the steering linkage that means even if you have everything tightened up there will still be play, and the front tires can dance like when you've seen a shopping cart that is beat up and the front wheels just move all around.

 

[throttleissues]

Crossover will also get the same wobble, but the cause of the actual movement are a little bit different. Any sideways movement indused in the axle (spring or shackle flex for example) causes the axle to steer itself since the box tends to stay still. It steers back and overshoots center, causing it to steer back the other way, turning into an uncontrollable wobble.
The point is, either steering setup can get DW. Most of the same parts will contribute to it either way. Steering stabilizers and hydro assist cyls help a lot, but worn out parts are going to cause it to come back if they're not fixed. Bent or out of balance wheels can start it, too. Check the steering box mounting area for cracks, pitman arm for coming loose. I've seen every one of these lead to DW on one rig or another. One problem that has SO many possible causes.