Wobble

1999 Tj with a 2" Tera Flex lift. After a Moab trip terrible death wobble started at about 45 MPH. Replaced the track bar. Could feel wobble trying to start in steering wheel. After about 20 miles death wobble came back big time. Swithched from 30" stock tires to offset 32" MTR's. Wobble stopped. However, I can still feel the wobble trying to get started at 45 MPH. One of these days the wobble will win again. Alignment has been checked. Four wheel shop says they can't find any reason. Track bar is in good shape.

Any opinion on whether changing to Tera Flex swing arms will help by reducing any looseness in suspension.

It is a puzzlement.

Reply to
Trust5280
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Did the alignment dude give you a printout? What is your total caster? If you are near zero, or below zero, that is a problem. Otherwise, a steering stabilizer could be in your future.

Juice

Reply to
Jerry Newton

Caster angle shouldn't even be below 5.5 degrees, let alone zero. For a 2" lift, Caster should actually be between 6 and 7 degrees of Caster angle. Are you thinking toe-in?

Jerry

Reply to
Jerry Bransford

Reply to
L.W.(ßill) Hughes III

Reply to
twaldron

I had a front end wobble that was bad enough I stopped to make sure a wheel wasn't about to fall off.

Drove me nuts changing parts trying to nail it.

Turned out the clutch on the rad fan had gone bad. It was an amazing shake.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Trust5280 wrote:

Reply to
Mike Romain
7 degrees is the factory specified Caster angle for a Wrangler. If you try to keep 7 degrees with 4.5" of lift, you do get front driveshaft vibration due to excessive pinion angle. But 5.5 to 6 degrees is entirely appropriate and works well. It's the standard recommended Caster angle when you get to 4-5" of lift which won't cause any front driveshaft problems/vibrations but it does give you enough Caster angle to give good steering qualities. My own TJ is set to nearly six degrees and that worked very well with my 5.5" of suspension lift. It's when you try to get too close to the factory 7 degree angle after installing a tall lift when the front pinion angle becomes excessive for the front driveshaft and u-joint.

Jerry

Reply to
Jerry Bransford

Reply to
twaldron

Tommy, Caster angle isn't super critical but 2.5 degrees is clearly way under what it needs. I would try four turns of your control arms (lengthening the lower arms) and see how it feels. Just do the same number of turns on each arm and it'll work fine. :)

Jerry

Reply to
Jerry Bransford

Tommy, of course you caught this but instead of lengthening your non-existent adjustable lower arms, shorten your upper arms by the same number of turns. I was at about 3.5 degrees before and 3 turns brought my caster up to where I needed it.

And the tech was correct that the driveshaft has priority but he was clueless on limiting the Caster angle to only 2.5 degrees since the Caster can usually be increased well beyond that, to around 5.5 to 6 degrees, before the pinion angle becomes excessive for a 4 or 4.5" lift.

Jerry

problems/vibrations

Reply to
Jerry Bransford

Reply to
twaldron

Point taken. I guess I wasn't very explanatory. My point was to keep the caster on the plus side of zero, anything that you do to reduce positive caster works against good driveability. Thanks for keepin me on my toes.

Jerry

Reply to
Jerry Newton

Since someone is keeping you on your toes, your use of the words "plus" and "positive" contradict themselves. "keep the caster on the plus side of zero, anything that you do to reduce positive caster.."

Does positive caster rake the sp> Point taken. I guess I wasn't very explanatory. My point was to keep the

Reply to
twaldron

Reply to
L.W.(ßill) Hughes III

Reply to
twaldron

Just wanted to say you all saved me a bit on this thread. My TJ was having some DW issues. I had it toed out to compensate. I took it to the front end shop and they did an alignment. There was still DW. After reading the print out from their machine and reading this thread, I noticed the castor was set at 3.5. Yesterday I went out and gave the bottom two control arms 2.5 turns out. I drove it all day yesterday with no DW issues. A big thanks.... The new owner of the TJ is flying in from Las Vegas tomorrow and I was having a cow, trying to figure out how to explain the DW to him. Now he can have a nice drive back. For some reason I didn't think there was a link between castor and the dreaded DW.

Have a great day.

--James

Reply to
RocknTJ

Insufficient Caster (not castor, which is like Castor Oil) angle can contribute to death wobble and other problems like twitchy steering and poor steering wheel return-to-center.. But do check two other things too because they can trigger death wobble while insufficient Caster angle usually only lets it fully develop. Carefully check the passenger-side trackbar mounting bolt for tightness, it should be at 74 ft-lbs, and double-check the front tire balance. Both of those are also major contributors to death wobble, especially a loose trackbar.

Jerry

Reply to
Jerry Bransford

The guy that did my alignment checked the trac bar, doesn't mean I shouldn't double check it. The tires probably need ballanced, they always do. Tires usually spin around on steel rims, chunks of rubber usually fall off while off roading and weights usually come up missing.

--James

Reply to
RocknTJ

This is all interesting. After my lift I noticed, very subtle, a slight steering pull one way and then the other. Not death wobble at all but a little disconcerting. I chalked it up to 4.5" of lift (plus 1" body lift). But now I think I will check all the things mentioned here. Thanks Jerry.

Andy

2001 TJ
Reply to
Andy

Reply to
L.W.(ßill) Hughes III

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