The first automatic transmission to utilize a torque converter (rather than a fluid coupling) was the Buick Dynaflow, which was released for the 1948 model year. In normal driving, the Dynaflow used only the leading gear, depending on the torque multiplication from the torque convertor at decreased speeds. The Dynaflow https://gearboxauto96284.canariblogs.com/a-secret-weapon-for-gearbox-auto-49004736