The first automatic transmission to work with a torque converter (in place of a fluid coupling) was the Buick Dynaflow, which was launched to the 1948 model year. In standard driving, the Dynaflow employed only the leading gear, depending on the torque multiplication from the torque convertor at reduced speeds. https://gearbox-auto21740.blog2learn.com/81841640/rumored-buzz-on-gearbox-auto