The main automatic transmission to implement a torque converter (as an alternative to a fluid coupling) was the Buick Dynaflow, which was launched with the 1948 product yr. In typical driving, the Dynaflow utilised just the leading gear, relying on the torque multiplication with the torque convertor at reduce speeds. https://zionlamue.thekatyblog.com/32555675/the-smart-trick-of-gearbox-auto-that-no-one-is-discussing