Blower motor needs "rapped" in cold weather

[Hubba]

The title says it all. When it's cold outside, approximately 40-45 or less I have to take the cover off where the blower motor resides and rap it a few times to get it to start. Once that's done the furnace heats for the duration of time I need it. Shuts off when temp reaches thermostat setting and all. Atwood was not able to provide a reason other than possibly dust. The entire area behind the cover was air-cleaned. Anyone have this problem and were they able to solve it?

[mainah]

Sounds like the motor shaft bushings are dry.