SO WHATS YOUR TAKE ON THIS.

[fubar XJ]

The track bar bracket at the axle end is often the problem here. It's pretty thin, maybe 1/8" steel, and the hole where the lower end of the track bar bolts through gets wallowed out. Pull the lower T/B end and look at the hole in the bracket, if it's egg shaped then that's likely your problem, or at least a major factor in it. The fix is simple, take some 3/16" steel and match-drill it for the lower T/B hole, weld said piece of steel over the top matched up with the old hole.