[lineslinger]

Hiss,
Sorry to hear about your motors problems, heat is the enemy.
MAYBE you can find a bad bearing here or a warped ring there but when a motor demonstrates the type of protest yours is showing, the only real way to deal with it is to pull it and go through it. Keep in mind there is a trickle down effect, one sour part will definately affect the next in line, everything has to work together without hinderence otherwise it just becomes a lesson in frustration.
Save yourself some (maybe serious) cash and fix it now rather than try to "drive" through it. An SO is a valuable powerpant, don't think short term.