cujo8, you'll need to clean out the slots on the area where the brushes make contact. I think that's called the comutator, I not sure.
Clean out one end of a slot with a knife, little by little. Make a slot cleaner from an old hacksaw blade ground down to the size of the slot and clean out the rest of the slots or grooves.
That's the way I did mine and it worked fine.
This might not be OSHA or GM approved but it worked OK for me.
