You can jack up one rear wheel and with the engine in neutral parking brake off, other wheel blocked so you don't roll away, try to spin the wheel by hand. If it spins pretty freely it's an open diff. If you can't spin it or it is very hard to turn, it has some kind of limited slip setup. Is it a Chrysler diff or a Dana? In 93, according to what I read in the FSM, only Dana rear ends had the trac-Loc. Chryslers had the Sure-grip, a different type of limited slip diff. A trac-LOc is rebuildable a Sure-Grip is not. I'm not sure if the same is true for later years, I only have the 93 FSM for cherokees. The test should work for either the Dana or the Chrysler. <img src="/forums/images/graemlins/cheers.gif" alt="" />