went through this on an exhaust fan recently... flip the switch and it
just hums. I was about to replace it, when I pulled it out and looked
at it... it was dusty as all hell. Blew off the dust and hit it with
a coat of CLP (that's the firearm version of WD-40 and it won't rust,
and it's better... get it at walmart in the gun section for about $4 a
can)

Anyhow, my fireplace blower had a similar problem... no matter how much
lube I put on it, it still requires a little assistance to get moving
every now and again.

Long story short... lube it. What's the worst thing that can happen,
that you break it?