AR15L wrote:
OK, I raised the axle off the ground - no ebrake and neutral.
Should I test it a different way?
Even so, is it even worth rebuilding or just go with the Detroit Truetrac
or the Auburn Gear
Test it as I described with it in gear and both wheels off the ground. If it has a worn out limited slip (I seriously doubt it, most Cherokees don't have LSD contrary to what others here are saying) the wheels will still turn opposite directions but you may feel some resistance. If it's an open diff (most likely) they'll turn opposite directions with only a little drag from brakes, bearings, and inertia. If it has a good limited slip or locker, you won't be able to turn either wheel more than a small amount by hand.
For the uses you describe, it's probably not worth going with either one. Nobody I know who's owned a TrueTrac was very happy with it. Installation of either one requires setting up the differential gears again, which is not a beginner job if you aren't familiar with it. That Chrysler 8.25 requires a special tool for adjustment; you can make your own if so inclined but will need some fabrication skills and equipment.