Someone Made a Working Six-Speed Gearbox Out of Legos
6 SPEED LEGO ENGINE SHIFTS GEARS | Listen to the roar of this 6 speed LEGO engine as it shifts gears! Gearbox design by Dgustafsson13 https://bit.ly/2OFnN83 Video by Mad Brick... | By
Ultra Compact 8 Speed Sequential Gearbox - LEGO Technic, Mindstorms, Model Team and Scale Modeling - Eurobricks Forums