The 1st automatic transmission to implement a torque converter (instead of a fluid coupling) was the Buick Dynaflow, which was released with the 1948 model year. In ordinary driving, the Dynaflow applied just the best gear, depending on the torque multiplication in the torque convertor at reduce speeds. The Dynaflow https://gearbox-auto42974.blogocial.com/5-easy-facts-about-gearbox-auto-described-69561989