Clutch SG that's seen abuse

Bad Sport said
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.

Disassembly is a must with that unit, as unless it's already been done every nook and cranny is going to have iron dust in it. (even the clutch surfaces)
Someone said "ran fine afterwards" so maybe they already did all that, but you can't count on it.
If it gets put in without, it could very well take out the bearings and gears that it went in with now.