It had been 1st released in 1939 for cars. It includes the fluid coupling and three planetary gears. They collectively make a few ahead and one reverse speed. There isn't any clutch for engagement and disengagement from the motor. Spur and helical gears are Utilized in the sliding mesh https://gearbox97429.thelateblog.com/34302600/a-simple-key-for-gearbox-unveiled