Clutch components. Epicyclic. Clutch components 2. Slinding mesh gearbox. Helical gear. Advantage; low noice level, highly efficient, Double-Helical. Advantages; more torque, more contact, The spur gear. Advantage; minimizes side thrust, double row. Advantages; straight cut teeth, low energy, Plate clutch. Constant mesh gear box. Synchro gear box. Dog clutch gear diagram.