Recheck the Drum and inspect very carefully - those Drums are known to crack easily and the crack may flex any you may not know it's cracked especially at the welded seams. Also you may have coins inside the baffles of the drum (remove the (3) baffles by removing (3) 5/16" screws and you might find coins trapped in there or something else). You can also remove the front support and inspect the front support roller wheels, then remove the drum and then inspect the rear roller wheels. Typically if any debris is wrapped around the rear roller wheels it will seize the wheel then wear out and then they will need replacing. Let us know what you find.