I have been tracking down my bumps steer for over a year. I noticed it when I had my BB and OEM trackbar. I upgraded to the JKS with minor improvement (no more bake pull). Next, I upgraded to the KOR Durometer bushings with no improvement. Then replaced my the Moog SS (Advance Auto warranty) since the bushings were already shot ( used the wrong sleeve ). This helped a little bit.
So after hearing from Kolak about 'ovalled' TB brackets I ordered new MOPAR TB bolts and found some matching washers to have welded to the bracket later this week. The only 'play' found was the axle side TB bushing. I noticed the original TB bolt had a shoulder near the bolt head and slightly tapered down to the threads. The New MOPAR bolt had no shoulder and had a thicker diameter all the way to the thread. Sorry I did not take pics or measure with calipers for proof. So the new bolts alone made a huge difference. Too bad I have an IRO aux SS that will be unused.
Well my bumpsteer has slowly returned.... Just when I fix something, another thing pops up.. I just replaced the rear a-arm and ball joint which helped wandering big time. I purchased another MOPAR TB bolt for the frame side and will install that this weekend. I'm getting read to ghost ride this Heep into the Chesapeake Bay.
I picked up another axle side bolt to use on the frame side last night and installed it. The frame side bolt also had a tapered shank. So far so good on the drive to work today, I wont hold my breath. I noticed that when applying pressure to the frame side mounting bracket with a pry bar it has some give to it, looks flimsy... I dont think the engineers really put much effort into the front and rear suspension on these WJs.
I need to do this as well. The bumpsteer and wandering on the road are killing me. I finally solved the problem on my XJ going to all heims on the steering and track bar plus hydro assist, and now I have the same ****ty steering on my newly acquired WJ. That and the rear bilstein rattle are driving me insane.
So has there been any resolution to this bump steer issue? I understand you tighten everything down and then tighten again, air down front tires, possible wallowed out track bar/control arm mounting holes, and most of all - the correct trackbar/drag link geometry. So say that you've done all of that, what's the next step? From what I understand, it's all about that geometry, but I've never read how to correct that bumpsteer. A lot of people frown upon the DPA and TB Bracket so how do you adjust the geometry? You could adjust your track bar length only so much before your axle is off-centered.
I've pretty much done everything above, except for the wallowed out hole/washer weld technique along with the trackbar bolts with a nice shoulder...still have quite the bumpsteer.