I had a similar squeal coming from my Atwood Furnace on our '97 Excella. It just started to make the noise as we were returning home from a trip last week. After reading above, I decided to tackle the problem yesterday. First, I Googled it and came up with this incredible find on You-Tube: All Seasons Mobile RV Repair - Atwood furnace motor removal - YouTube
It takes this guy only about 8 minutes to pull the motor from the unit. I copied what he did, but first I took several pics so I could get the wires back exactly right. It took me about 20 minutes to pull the motor, following his steps.
With the motor out, I first decided to check out my own motor instead of just rushing off and buying a new one. I started by "unbending" the little metal tabs which hold down the endcap of the motor, electrical connection end first. Then with a small flat screwdriver I carefully removed the electrical connection endcap. It came off fairly easy. Inside, the cap I could see the motor did not have a roller bearing, but only a steel bushing and all lubricant was gone. I carefully relubed the bushing with wheel bearing grease. I used grease because I read that someone had "oiled" his but the squeak came back. Then I reassembled the endcap onto the motor housing. I was careful to gently move the cap onto the armature until the brushes came up against the armature then I used an ice pick to reach in and gently move each brush onto the armature, then gently pressed the endcap into it's final position, then bent the metal tabs to hold it in place. Then I did the other end of the motor. It was a bit easier because there were no brushes. Be sure to somehow mark the endcap and the motor body so you can relocate the endcap to it's exact former position upon reassembly.
The whole procedure took about 20 minutes.
Tolerances between the bushing and the shaft were fairly tight so no slop. My brushes seem to have about half of their length remaining so they should last for years.
I installed the now lubed motor back in the furnace in about 15 minutes, and turned it on and let it run for about 20 minutes. Aaaah success! Nice and quiet.