It was initial introduced in 1939 for automobiles. It is made up of the fluid coupling and three planetary gears. They collectively make 3 forward and 1 reverse speed. There isn't a clutch for engagement and disengagement with the engine. Most transmissions in contemporary cars and trucks use synchromesh https://dantejjhec.tusblogos.com/34038046/the-greatest-guide-to-gearbox