Examine your bearings when you clean them, if there is a brownish/black stripe on the rollers, this indicates scorching & the bearing should be replaced.
Last time I did mine, I had one inner scorched.
A quick trip to auto zone or advanced auto, checkers, etc. will get you a new one...
Pounding out the race(pin or tapered punch, look from the back side for the notches) & replacing it with the new one that comes with the bearing, is the hardest part...