While you have the smoke unit open, you might want to at least place a small amount of oil on the other fan motor shaft. I place a small external DC power to work the oil into the shaft. Listen for the improved sound of the motor.
Also, there is a small red gasket on the DSMK units that is easily broke when you pull it apart. Lionel does sell these as an individual part. I have to replace them about 50% of the time. Usually when the smoke unit has been over heated.
