Our furnace is under our fridge. I changed out our motor completely from the outside of the coach. Use a long Allen wrench through a cutout in the squirrel cage blower to loosen blower. Remove single motor clamp. Motor comes out and a new one goes back in. Squealing motors are common and replacement motors are readily available. We also changed out one blower as we thought it may have lost its balancing weights.
You can do it yourself by Barry and Cindy 1997 U270 36'