Put Teraflex 9550 shocks on the TJ, now have wobblies
- Thread starter TJustin
- Start date
waynehartwig
www.jeeperman.com
- Location
- Mead, WA
IMO toe is the biggest factor in death wobble - assuming everything in the front end is tight. Others think caster/camber can cause it, but I don't.
But I did say above that less than 1/2" probably won't cause it. I'm looking for bigger numbers like 3/4" or 1". Not 3/8".
- Location
- Payson, UT
Well, I just got done putting my new Teraflex Track bar on.... Not the issue. Everything is tight.
It might be headed to the alignment rack this week...
It might be headed to the alignment rack this week...
JackKeslerCustoms
Active Member
- Location
- Herriman
I'm back to my origional diag then. I think it's bad geometry. The camber and caste are the measurements of the wheels in relation to where the factory says they should be, and the angle of the axle/steering. If you put on short arms with tall springs, it rotates the axle into a position that the control arms have to move forward and up when you hit a bump.
waynehartwig
www.jeeperman.com
- Location
- Mead, WA
How much lift do you have?
- Location
- Payson, UT
Its got a 4" on it. When I had the alignment done the shop told me that the caster was way off, but there was nothing that could be done because of the fixed Lower control arms.
waynehartwig
www.jeeperman.com
- Location
- Mead, WA
Pinion/driveline geometry trumps caster adjustments. Meaning that your pinion angle needs to be set so you have no driveline issues or it will ruin your pinion bearings/u joints/etc.
Post a picture of your pinion angle.
Also, get you a magnetic angle finder from Home Depot for like $10 and check your caster angle - simply put your rig on flat level ground, and put the angle finder on the ball joint. It should be ~7*. Just see what you have. 4" of lift should not be making the caster 'way off'. Look on the road at how many have short arm suspensions with 5" of lift and they aren't having the issues you are or there would be these types of threads all over the place.
I'm still with Bryson....You've got something loose that you aren't finding.
- Location
- Payson, UT
Its at 9*
waynehartwig
www.jeeperman.com
- Location
- Mead, WA
That's not too bad. Spec is +7*, +/-1*.
You can try changing your pinion a little and see if it causes driveline vibes. You might get 1-2* out of it and be able to get back into spec. The only thing 9* over *7 is steering will feal a little 'heavy'. Some vehicles have a higher caster spec, like what you are seeing.
But I don't think your issue is caster related. Keep looking for something worn or loose.
EDIT:
Have you checked your steering? Like steering shaft, steering box, pitman arm, etc.?
I'm gonna have to disagree with Wayne here--caster needs to take precedence over pinion angle. If it doesn't drive down the road well, then vibrations don't matter anyway.
9 degrees is way off. The stock 7 degree spec is for stock tires. The larger your tires are, the less caster you need for the same "feel". Try setting it closer to 5 degrees and see how it feels there.
9 degrees is way off. The stock 7 degree spec is for stock tires. The larger your tires are, the less caster you need for the same "feel". Try setting it closer to 5 degrees and see how it feels there.
- Location
- Payson, UT
Is this something I can do in the driveway? Won't it mess with the toe?
Corban_White
Well-Known Member
- Location
- Payson, AZ
JackKeslerCustoms
Active Member
- Location
- Herriman
What Uppers are you running? A lot of 4" kits re-use the stock uppers.
- Location
- Payson, UT
Stock uppers.
JackKeslerCustoms
Active Member
- Location
- Herriman
I feel like I'm beating a dead horse here, but I think the root of the problem is the short arms. 4" kits that use the stock uppers tend to really increase the angles of the control arms, and the stock uppers are notoriusly weak, and prone to bending / breaking. Then you've added the Rusty's lowers, which hopefully are made to work with the stock uppers, and are long enough to correct the pinion angle, and caster. I think Carl is right about correcting the caster fist, but then I would take it to a reputable shop (i.e. Teraflex is the first that comes to mind) who installs kits all the time, to not only check the alignment but also measure the wheelbase and look for any other possible causes.
- Location
- Payson, UT
I looked around on Jeep Forum and other websites to see if I could get a more accurate reading of my caster.
I found one that said to take a straight edge and put it over the front of the upper and lower ball joints, and if this works as well then I am getting 11-12* in camber.
I am planning on attacking the issue tonight to fix at least the camber issue.
Any advice before I tear into the beast?
I found one that said to take a straight edge and put it over the front of the upper and lower ball joints, and if this works as well then I am getting 11-12* in camber.
I am planning on attacking the issue tonight to fix at least the camber issue.
Any advice before I tear into the beast?
JackKeslerCustoms
Active Member
- Location
- Herriman
I think your looking in the right direction.
- Location
- Payson, UT
K, I have shortened the LCA's as short as I can get them and am still looking at 7-8* but feels a ton more controllable. I never realized how straight it could track until now. I will probably end up buying uppers to compensate and get it even lower.
I did still get it to wobble BTW but it was on some pretty intense bumps in the road, I went to the usual spots and tried forcing it to do what it normally did. They were eliminated.
I did still get it to wobble BTW but it was on some pretty intense bumps in the road, I went to the usual spots and tried forcing it to do what it normally did. They were eliminated.
Lifelong Jeeper
Well-Known Member
- Location
- Murray
worn or fatigued upper/lower control arm bushings could also be contributing factors. Based on my previous debilitating death wobble, caster had everything to do with it (come to find out after replacing all of my steering components and track bar which didn't fix it).