In my years of fighting with XJs, track bar and wheel balance seem to be my Jeep's weak points. Four years ago, I had a set of Cooper Discoverer HTs that would not hold a balance. On my '96 just recently, I got rid of a set of Dayton Timberline ATs. Both sets were about two years old, about 30k miles, 235/75 on factory wheels, replaced both sets with 235/70 car type tires, both vehicles run smooth. Toward the 30k mark on both sets, even when balanced, they were out of round. The XJs are light, and a truck type tire, for normal on-pavement driving is just too harsh. Have it be a little imperfect, and look out!