Fan blower squeals

Hello group,
As the weather gets colder (here in Wisconsin) my fan blower begins to squeal now and then. It is not consistent. At first I thought some dry leaves could be causing this, but after carefully blowing everything out under the hood, the problem persists. Is there some area of the blower that could be lubricated easily? I'm told that replacing the motor could run about $300. Reluctant to part with that sum for the moment.
Any help/suggestions would be greatly appreciated.

Luis
'91 300TE 4Matic
103K mi.
(I love this car!!)

[haasman]

Luis,

this site's search feature will turn up a ton of info on the topic. Here is one for you:

300E blower

Haasman