I pulled the posi carrier out of a junkyard '98 Dakota 4x4 with an 8.25 differential. Before removing it, I couldn't spin an axle by turning its wheel-mounting flange by hand, but when I used a 24" bar to pry against the wheel-mounting studs, it took firm but not too much force to move, perhaps 10-20 pounds force at the end of the bar. When I get the clutches disassembled, how do I know how worn they are? I don't have new clutch parts to compare them to. If they look okay but I want to add more slip resistance, can I shim them to achieve this, or is there a better method?