Strong wobble

[sssboi]

Hey guys

It's been happening a few times now at about 80kmh sometimes the car will decide to violently shake and vibrate. It only happens sometimes making me think it was the road surface, but the shake is identical each time. Obviously when this happens I'm on the brakes to slow it down but it tends to wobble a bit under braking as well. As far as mods go, the car recently had new rancho shocks installed and a 1" coil spacer lift. Any ideas? Cause the wobble is scary and uncomfortable as hell!


Edit: I had the shocks and spacers installed, brake fluid flush, transmission service and the handbrake adjusted. After this work was completed I noticed this wobble

[nitrobrent]

Save this link http://www.jeepz.com/forum/suspension/29510-wrangler-death-wobble-what-causes-how-fix.html
I would start with No. 4.Easiest and most likely.Its not the end of the world,you will fix it,probably more than once too.
Brent

[bonza]

you have probably got death wobble, and first thing to check is the front trackbar (sometime known by the stupid name panhard) bolt where it connects to the axle housing.
to check looseness get someone to turn the steering wheel from lock to lock an see if there is any looseness in ball joints, control arms, trackbar etc.
the trackbar axle mount bolt is M10, and if looseness is observed tighten up to 40 ft/lb.

the M10 bolt used in this application for some silly reason has the shank machined down to 9.5mm so there is 0.5mm play from the start which doesnt help, hence the reason to ensure this bolt is kept tight. the track bar is kept in place by clamp force of a very tight bolt rather than the precision fitment of bush and bolt as is common engineering practice

if tightening up doesnt work because the bolt hole is flogged out you will need to go up a size

the next size up is 7/16" (a tad over 11mm), so get yourself a 7/16" x 3" long grade 8 bolt and drill out the hole and trackbar bush to this size so it is a nice precise fit. a grade 8 7/16" bolt can be torqued up to 80ft/lb.

next size after this is M12, but this is quite a step up and not much room for the nut inside the trackbar axle bracket, hence the logic of going 7/16"

[sssboi]

Just saw victor at blackjack welding and he tightened up the bolt on the panhard. I've since greased all the bushings I could find under the car. Will take the car for a drive and see how that goes.

[TassieTJ]

the bush will be worn and the hole which the bolt goes through in the diff end, very common very easily fixed

[garth]

had the same issue on mine, hit around 80kmph and it would feel like it was tearing itself apart, also would happen when i had a bump.

where the bolt slides threw the track bar on the axle mount it was worn, i drilled it out to a 12mm hole, drilled the centre of the track bar to 12mm, installed a bigger washer on the front side, and put in a 12mm h.t bolt and nut. nice tight fit, it's wonderfull, no-more wobbles.