It absolutely was 1st introduced in 1939 for automobiles. It consists of the fluid coupling and 3 planetary gears. They collectively make 3 ahead and just one reverse velocity. There isn't any clutch for engagement and disengagement from your engine. They've a substantial transmission fee and significant bearing means. https://gearbox30516.myparisblog.com/34344027/not-known-details-about-gearbox