The very first automatic transmission to use a torque converter (in lieu of a fluid coupling) was the Buick Dynaflow, which was launched for your 1948 product yr. In ordinary driving, the Dynaflow employed just the leading equipment, counting on the torque multiplication of your torque convertor at reduce speeds. https://gunnerrwwxw.eedblog.com/34248088/gearbox-auto-no-further-a-mystery