Do this. Have someone start the GC and turn the wheel left and right. You get in front and look at the link between the drag link and the pitman arm. Is it going up and down as the wheel turns? If so it needs to be replaced.
Now you mentioned wheel hub units. If, with the wheel off the ground you can move your tire/wheel back and forth then your wheel hubs are going. Up and down movement indicates bad ball joints.
And leaking grease boots will ruin the joint some can be replaced.
That should get you started.
'95 ZJ Ltd. White 4.0L
TW DC DS; ARB Bull Bar, F&R Air Lockers; Superior Axles; Warn Winch; 4.56 gears; ACOS, Addco F&R Sw Bar, JKS Discos, Rr Track Bar & Nerfs, 249>242 Swap, Stillen rotors+Kolak pads, 3 pc. Armor, RE 4.5 Kit + 2.5"BB, Adj. UCAs&LCAs, OME SS, Bilstein 5150s, 15x8 AR Diamond Backs, 33 Truxus MTs, K&N FIPK, RE 62mm TB, Perf. Distr. 4.0L Kit, Exhaust: 2.5" Kolak exhaust FM 70: Optima Yellow, Mean Grn Alt., PIAA 520s, 540s, Kevins Rack, & TB Conversion