Death wobble at 55

[Frog975]

Ok here it goes, i have a 98 XJ. I have Rusty's 6" coils and rear leafs. I have RE solid upper and ADJ LWR control arms. I have the RE ADJ track bar, and JKS Disco's. My UCA's measure 15", and i just set my LCA's to 16 3/4", and now if i hit a bump I hang on for dear life and hope that my axle stays under my jeep. I just extended the LCA's tonight from 16 1/2" to 16 3/4"s, would this make it wobble like hell at 55? It did it a very little when i had the LCA's set at 16 1/2, or is it worn out TRE's and maybe a steering dampner????? HELP PLEASE, this is my daily driver and i'm lost. Any help would be appreciated.

[89xj]

you need to measure caster angle when you change the lenghts of the control arms. you should be close to 5 degrees positive caster.

since the only thing you did was change the contol arm length, i would say that is your problem.

[RCP Phx]

Dw isnt really about lift,Ive had it on 4 out-of 4 (2-stock)Jeeps.It is about wheel balance and alignment specs(and geometry) along with loose or worn parts.Control arm lengths dont really help,what is the castor?Youre at a bit of a disadvantage with that much lift and no drop brackets,that can certainly help set things off!Steering dampners are just a "mask".Larger tires and less backspace wheels also seem to aggrevate the situation.

[Frog975]

Ok how do i measure the caster angle. I saw it posted once, but it confused the hell out of me. It was writtien for a rocket scientist i guess.

[89xj]

i agree that DW is a about alignment and wheel balance, but since the only thing he changed was control arm length, i would think that was his problem. i guess i jumped the gun.

i guess i am wrong, but i thought caster was how much the axle(steering knuckles) is tilted from its vertical axis and was controlled by the lenghts of the control arms.

[RCP Phx]

Another example of why DW never makes sense !! Most will say a "lack" of castor will contribute to DW.If he lengthened his lowers he was increasing the castor.

Ps:89xj,read the post times,I was replying to Frog!

[utahxjer]

Go ahead and make sure that trac-bar is tightened down at the frame mount, do you have the HD mount as well? If not I would get it. I like Rockkrawler's HD trac bar mount, better than RE's. www.rockkrawler.com

[Frog975]

Yes I do have the HD tracbar, and it is tight. Last night i shortened my LCA's back down to 16" and it seems to be driving ok for now. I'm going to replace all the TRE's, and get the wheels balanced,and a good alignment too. I'll see if that makes it better also. Thanks for all the help guy's

[xj4rocks]

this has already been mentioned but CHECK YOUR WHEEl BALANCE :: if you're having DW at 55 then I'd put money down that it's an out of balance condition. The wheel speed at 55mph is the right frequency that the out of balance condition really becomes noticeable. Usually it will go away to an extent at higher speeds also.

Even if you think you're wheels are balance go have them checked anyway. Just recently I started getting this again and had my tires (which are street only and have been balanced twice at least) balanced again. Shake went right away.

So to end this post.....check your wheel balance......