PS: Please don't ask me why I know this...

Good point about drum damage. Speaking hypothetically, that could take the form of a small crack in the hub, the thickest part of the cast iron drum in the center where the bearings run. Aside from the implications about structural integrity of the drum, this could allow grease to leak out of the center of the hub and be flung up onto the brake shoes and machined braking surface of the drum. Well, maybe a little more than hypothetically....

Chip Bearden
"JB"