hi art. Bearings are metal and wouldnt have any plastic parts - in addition a broken bearing would rattle like hell and be quite obvious. The bearings are covered by a rubber seal. might be bits of the seal breaking up, though seals are generally black rubber. May be damage to the outer drum if its made of plastic. Loose coins and other debris flying between the drums at spin speed would certainly gouge out lumps of plastic and could easily hole the drum.
If i were you id disconnect the sump hose (the big one which connects to the filter or pump) from bottom of drum and stick my fingers in to check for coins etc.
Check out my site for info: www.2ndwave.co.uk/manual.html
dan
March 2008