I just finished my lift and went and got my alignment done. I've noticed when I hit certin bumps my front end starts shaking violently, so I got under my jeep and looked around and noticed that my adjustable track ARM has a lot of play in it as meaning I can move it from side to side, would this cause my front end to shake like that? Please help!
05-07-2011 10:20 AM
Yep that would be your problem the track bar should not have any play
05-07-2011 11:01 AM
That violent shaking has become known over the years as "Death Wobble". The bigger the tires and the further out they set from the axle, the more Death Wobble becomes a problem.
The most common combination that sets off DW is a bump in the road or out of balance tire that serves as the triggering event, followed by something in the front-end that is loose enough to allow that "event" to develop into full-blown DW... like a loose track bar as you have.
As T2000J mentioned above, there should be ZERO side-to-side play where the track bar is bolted to the axle on the passenger side. Get that resolved and then get your tires perfectly balanced. Tell the tire balance guy that you'll give him a little extra tip to take a little more time to get your tires perfectly balanced rather than just "good enough" like most shops get them to. "Good enough" is not good enough for a lifted Wrangler with bigger tires.
Finally, make sure your toe-in is set properly. A bad toe-in setting can encourage DW, the same with too much caster angle.
05-07-2011 06:06 PM
Ok thanks Jerry, what exactly is a tow-in I saw it on the alignment sheet they gave me but wasn't sure what it was
05-07-2011 06:25 PM
Toe-in is how the tires track. More toe-in sets the tires so the front of the tires are very slightly closer together than in the rear.
Rear-wheel drive vehicles like the Wrangler require just a tad toe-in.
Front-wheel cars like Hondas and Toyotas require just a tad toe-out.
05-07-2011 06:31 PM
Ok, I don't have the sheet they have me right now saying what the tow-in reading was but I will repost later with the before and after reading and get your opinion on it, thanks again Jerry.
05-07-2011 06:32 PM
Sorry I ment the faster setting cause if I remember right it was in the red and everything else was in the green
05-07-2011 06:38 PM
What does your report say your Caster angle is at? And what size tires do you have?
05-07-2011 06:40 PM
I have 31-10.50-15 and I will have to get you the caster reading I don't have the sheet on me right now
05-07-2011 06:42 PM
6-7 degrees of caster setting is the factory setting for stock size tires. However, the exact caster angle is not critical and the desired caster angle does decrease slightly as the tire size increases. My TJ's caster angle is somewhere between 4.5 and 5 degrees which is good for larger tires like my 35 inchers.
So long as the steering wheel wants to straighten itself out again after you complete a turn, called having a good return to center, the caster angle is very likely ok.
05-07-2011 06:51 PM
Ok will still put the readings in here later for you to look at, thanks Jerry
05-07-2011 06:58 PM
Oh yes I forgot to menton I have a 4in lift and was told that I didn't have to use the drop pitman ARM, is that correct?
05-07-2011 07:08 PM
That is correct. For 99% of all lifted TJs, installing a dropped Pitman arm will only cause bump steer. The only commonly encountered valid reason for installing a DPA is if the driver's side (upper) track bar mount has an aftermarket dropped mounting bracket installed. If the upper track bar mount is dropped, the Pitman arm must be dropped. If the upper track bar mount is stock and un-dropped, the Pitman arm cannot be dropped. They have to match... dropped/dropped or undropped/undropped.
05-07-2011 07:48 PM
Ok I put the rough country adjustable track bar on mine
05-07-2011 09:09 PM
Ok the passanger side is 5.5 degrees and the drivers is 5.3, and this is with the alignment