Hi N Scalers, I just bought a used Kato SD70M ElectroMotive demonstrator (red). No box so no numbers, but I'm sure it's an old style chassis. It sounds like it has a bad gear, likely front truck. Truck does not want to snap out. Do you have to loosen the screws holding chassis halves together on this type chassis to remove the truck? I've never dealt with this same chassis before. Pic attached. Thanks. Lowell.