The worm gearbox takes advantage of a substantial diameter warm wheel. A worm or screw meshes with teeth to the outer circumference of the gearbox. Manual transmission gearboxes have a clutch that engages and disengages the engine in the gearbox, plus a equipment change lever that selects various gears. https://gearbox97429.full-design.com/an-unbiased-view-of-gearbox-76198951