The driving force works by using the gear lever to vary or shift the equipment. The lever moves in a selected way As outlined by style and design. It was first released in 1939 for vehicles. It is made up of the fluid coupling and a few planetary gears. https://lorenzohcqes.pages10.com/how-much-you-need-to-expect-you-ll-pay-for-a-good-gearbox-69160541