Tomy trains 2 speed gearbox repair

[Super]

Does the motor run but the train does not move or slips? My experience with these is that it is very common for the axle gear to split resulting in the motor still running but slipping on the axle. This often happens because little hands are holding the train still while its running or trying to force it to free wheel when the motor switch is on even without a battery. Is this what is happening? I have not come across any of the gears inside the motor housing splitting on these styles. I have only seen split gears inside the motor housing on one type of Plarail motor and that is exclusive to the western style steam engines.