As a temporary fix for our fifth wheel fan motor, I sprayed some high quality silicon lubricant into the fan impeller from the outside. It helped lessen the noise quit a bit. Our furnace used to squeal the whole time the furnace ran, now it has a short (1-2 second) burst when the furnace starts, but quiets after that. I know most people here are probably rolling their eyes at me as they read this, but it was a cheap quick fix until I can complete the proper repair.
Thanks for the input - I maybe would have tried that but I ended up getting a small space heater (which I wanted anyway) and since am heading south and probably won't really be needing the "big" furnace til next season I'll more than likely just put off the installation of the motor til then. BTW the little space heater I got is great. Smallish but great heat and only using it on medium draw (1125W). https://www.amazon.com/gp/product/B00MB4BQ0G/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
Great news! Yes we bought 3 small electric heaters last fall for the same reason. We are in a different rig but didn't want to rely solely on the furnace in case we ran into the same issues with the fan as we did on the fifth wheel :) 1 is bigger like yours , the other 2 are pretty small - max wattage 500, with a low setting of 250. So we kept 1 on low in the bathroom, 1 on high in the bedroom and the bigger electric heater like yours was in the main living area. They worked quite well all winter until about the end of Jan when we got a month long cold snap. Then the furnace came on a lot more.
That seems like a lot of labor time, especially if the guy doesn't have to travel. I wish I was there I would be happy to install it for you for free. Well, maybe a couple cold beers. :)