I have the motor disassembled and now I can see why they claim electric motor bearings should last lifetimes barring lubrication failure, arcing , or contamination, these things are massive. It looks like dried flakes of coolant or perhaps the corrosion the coolant did to the metal ends of the motor was the culprit, the grease itself was there without being excessive. The motor shaft end bearing has a bad feel and a little looseness and I believe it was just enough to cause the cup wheel to pound in a few spots and glaze up. I think when I put the thing back together I will make some sort of "flinger" from coffee can lid plastic just far enough from the motor housing to not rub. Although I can't complain about the service this thing has given me.
Thanks again for all the help. Tom