It absolutely was to start with released in 1939 for vehicles. It includes the fluid coupling and three planetary gears. They collectively make a few forward and 1 reverse pace. There isn't any clutch for engagement and disengagement within the motor. Bevel gearboxes have spiral and straight enamel styles. https://gearbox82692.get-blogging.com/34321344/the-ultimate-guide-to-gearbox