Its just alot more tedious than the old chassis mounted smoke units. The old ones you just remove the boiler, unscrew the top and change out the wicking or whatever, you didn't always have to remove the complete unit to work on it. I believe the shell amplifies any motor noise, even when its at a normal level.
The main thing is getting the fan impeller in the right position on the shaft, to close to the motor, or too far out and it will nick the housing, and its hard to tell how bad until you have it al back together and test it.
I know it really shouldn't matter but I think these motors do better when they're verticle( like they used to be) than run horizontally like in these new smoke units.
At any rate, good video Bobot! It does a good job showing Lionels new smoke unit design, and how to fix it, of course