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Need Help with Death wobble


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I had it after I did my lift....I had old tires on it that were worn out and most likely out of balance.

New tires,a full set of ball joints(Adjustable uppers) and a good alignment and its gone.

Tires made a huge difference,so in my case I would say tire balance mostly,I can't say how bad the ball joints were but I could see how bad the tires leaned in at the top and there was no way to adjust the camber(caster I get confused).But it drives smooth now well worth the money for piece of mind...

I think the ball joint set cost me around $200, adjustable uppers and standard lowers..

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With the inverted Y steering setup out Jeeps have, lift crates toe-in. Depending on what source, toe in should either be 0, or 1/16 to 1/8". I never thought about it and never worried about it. I added 1.75" spacer blocks, and all was fine. Then when I added 4.5" springs to the spacer blocks I had DW at speeds as low as 25mph. Severe enough to fry my alternator bearings. When I took my tape measure out I found I had a full 2 (TWO!) inches of toe in.

 

But because the nose of the Comanche gets narrower toward the front it was not obvious to the naked eye.

 

Set my toe to 0 and all was well again.

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Lift also results in less caster. Positive caster is when a line drawn through the lower and upper ball joints leans back toward the top, negative caster is when that line leans forward at the top. The stock configuration results in around 7 degrees of positive caster (upper ball joint is behind lower ball joint, line leans back at the top). If the caster gets less than 4 or 5 degrees, there is less tendency for the weight of the vehicle on the tires to keep the wheels tracking straight, and to self-cancel wheel shimmy. If wheel shimmy is not cancelled out and can be transmitted from one wheel to the other, you get death wobble.

 

This is why lifts require longer control arms, and why adjustable control arms are better if you want to be able to fine tune your alignment. The Catch-22 is that when you have a big lift, cranking the caster back to 7 degrees or more results in the u-joint angle at the front pinion becoming excessive, which causes rapid wear of the u-joint as well as vibrations. So it becomes a bit of a dance -- you have to try to find the compromise between caster angle and u-joint angle that prevents death wobble while not eating u-joints for breakfast, lunch, AND dinner.

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Moving the track bar left or right moves your axle sideways, but won't fix DW unless the original hole was wallowed out.

 

My money is still on the upper end of the track bar, Either the mount being loose or hole wallowed out, or loose bolts holding the bracket to the frame.

 

But i can't remember if you rotated your tires front to rear yet to rule out a tire problem?

 

Also I have driven my truck with anywhere from -0.5 to +7.5 degrees caster without DW. -0.5 gave me a much better drive shaft angle, but was extremely squirrelly on the freeway. I currently sit at around 4 degrees to get some road manners back.

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Every thing is perfect but the steering wheel is off to one side now whats up with that.

good deal, LCAs is what fixed death wobble on my stock height truck.

 

to center the steering wheel drive straight ahead (like down the driveway or something then park (with the tires straight ahead, steering wheel off) then loosen the bolts on the sleeve that goes from the passenger knuckle to the pitman arm, and rotate the sleeve until the steering wheel/pitman arm are centered up.

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