Could be. You may need to take the shell off and make sure that the
drivetrain is all in tact. When you say you can hear the motor "run" I am
assuming you mean it is actually turning and not just buzzing. Otherwise,
I might also suggest that the gears may only need lubrication, or that
there could be an issue with the motor after all.
If it is the gears or a drivetrain part, I would assume you could order
those from Bachmann somehow. I have never tried to repair one of their
locos so I am not much help beyond what the problem could be. :) * SLMR 2.1a * All animals are equal, some more than others.