Clutch SG that's seen abuse

The only thing I can think of would be metal shavings, and possible cracks.

Inspect it really well, and possibly take it apart and inspect/clean it.

IF you do take it apart, mark the case where it splits so you can align it when going back together, AND pay close attention to how the clutches are installed, maybe even replace them.

Pics are a plus as you disassemble.