For the first time I tried taking apart several N scale engines in order to try performing maintenance and lubrication. I was able to remove the couplers and shell, and the next step would be truck removal. I hoped this would allow access to more gears and the motor and associated parts. I have only taken apart Atlas engines, and you just had to pull down on the trucks to remove them. I have tried this on the GMD-1 no luck, but possibly I am not using enough force. I'm afraid to damage anything so before I really apply force, just wanted to check and see if anyone has run into the same situation.
Thanks John. I actually contacted Rapido and they said to send them in. They have a lifetime warranty. They advised to send all four in! Free tune ups. This is a solution, but if possible, I would have liked to try this myself. And save the postage costs.
Outside of Canada, I think there is only one in the US #1413 on the Oregon Pacific and 20 in Cuba on the Ferrocarriles de Cuba. #1413 has a nice paint scheme.
Another just went into service at the refinery in St Paul Park MN as the contractor switcher for northern plains rail service. Nice solid blue paint scheme.