I picked up a Proto2000 GP20 at a show the other day, and have been working on getting it running again. After cleaning the drive train (including the gears going to the axles), the locomotive runs smoothly.
However, upon reassembly the flywheel on the long nose end rubs against the weight. I attempted to repair it by removing, checking, and reinstalling the motor, but only succeeded partway. The flywheel still rubs against the weight, but not as badly.
How can I fix this? I'm not sure if it worked correctly in the first place, since the lube had set up the wheels wouldn't even turn.