@Fish, you were right on!! I removed the grid on top of the fan. Then I could just pull out the crank shaft. There were 6 ball bearings inside. They didn't look that dirty but I went ahead and cleaned them. I also cleaned the inside with with some Acetone that I poured onto a towel. After that I added some WD40, removed the the excess and reassembled everything. I didn't think it would make a difference because it really wasn't that dirty but indeed the screeching went away, at least for the 20s or so I ran the engine. Thanks so much!!