Fixing up the Lego Steam Cargo Train (7722)
ⓘ These instructions may also apply to other Lego 4.5V trains such as the Diesel Freight Train
- Remove lid from battery box car and clean contacts, e.g. with vinegar to remove battery corrosion
- Using a small knife or screwdriver, spread the contacts of the cable that plugs into the motor so it makes better contact
- Out of the box the contacts are too small and loose on the side that connects to the motor
- If there's a squealing sound coming from the motor box, it can be disassembled and lubricated