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View Full Version : Anyone fought death wobble in an xj?



sxpimpin
04-15-2011, 08:32 AM
I'm not sure if anyone here can help me or not, but I figured it would be worth a shot.

I guess I'll start out by telling you about I've done to the jeep.
1989 Jeep Cherokee XJ
6.5" rusty's lift kit
fixed short arms
HD adjustable track bar
JKS quicker disconnects
Rancho Stabilizer
33" mickey thompson baja mtzs
SYE kit, with tom woods drive shaft
New steering box/Drop pitman arm

Here's my problem, I've been experiencing death wobble BAD. It only happens at 33-35 mph on my speedometer which is really around 40mph. If I accelerate semi fast and break a little harder than usually I barely feel a shake in the steering wheel. Problem is im constantly stuck in traffic around town that does 35/40mph and the slightest bump will set my front end off. I've been through the ropes checking the front end. Tightened all bolts, checked EVERYTHING for play, measured toe, checked the wheelbase, ect ect. Yesterday i was sitting under it thinking something would stand out and bite me. I then noticed that one of the springs is touching the knuckle on one side and 3/8" away on the other. Would this cause death wobble, and couldn't I simply adjust the trackbar?

VWBobby
04-15-2011, 09:32 AM
I'm not a Jeep guy but I know a lot about setting up suspensions.

If the spring is restricting your steering or binding up the knuckle, that is a serious issue. Either it will bang into the spring on bumps/braking and cause a bump-steer effect (sudden diving different directions) or it will restrict the turning circle.

2 major factors in bump steer are toe-in and caster. Most vehicles respond better to at least 1/4" - 1/2" of toe in. It depends on how flexible the suspension is. If the toe in changes a lot during braking or turning, you might need more.
Caster affects your steering angle of the wheels. How vertical the knuckles are in relation to the suspension.. If they are too straight (0 degrees caster) then the car will tend to understeer. If there is too much caster, the car will try to oversteer or dive and bump steer.

Although rare, wheel balance can also cause a death wobble. If you wheels are out of balance, you can get odd vibrations and weird handling at a specific speed or range (30-35MPH for instance). The VW Superbeetles in '73-79 are known to have the "supbeetle shimmy" at 30-35MPH due to worn suspension. :) Only way to correct it is to have VERY well balanced tires or perfect (new) suspension. :(

BigSix
04-15-2011, 10:12 AM
I'm not sure if anyone here can help me or not, but I figured it would be worth a shot.

I guess I'll start out by telling you about I've done to the jeep.
1989 Jeep Cherokee XJ
6.5" rusty's lift kit
fixed short arms
HD adjustable track bar
JKS quicker disconnects
Rancho Stabilizer
33" mickey thompson baja mtzs
SYE kit, with tom woods drive shaft
New steering box/Drop pitman arm

Here's my problem, I've been experiencing death wobble BAD. It only happens at 33-35 mph on my speedometer which is really around 40mph. If I accelerate semi fast and break a little harder than usually I barely feel a shake in the steering wheel. Problem is im constantly stuck in traffic around town that does 35/40mph and the slightest bump will set my front end off. I've been through the ropes checking the front end. Tightened all bolts, checked EVERYTHING for play, measured toe, checked the wheelbase, ect ect. Yesterday i was sitting under it thinking something would stand out and bite me. I then noticed that one of the springs is touching the knuckle on one side and 3/8" away on the other. Would this cause death wobble, and couldn't I simply adjust the trackbar?



ohhhhh boy death wobble......not fun I tell you .....its actually scarier than a roller coaster ride.....I had a 97 jeep wrangler all stock and had it going bout 65 on the highway one day......felt like my car was gonna explode!!!! I got a stablizer and never had it again.....although they said its a quick fix......pretty common with jeeps.....as I was told it can be a number of things.....Good luck to you sir