The initial automatic transmission to make use of a torque converter (instead of a fluid coupling) was the Buick Dynaflow, which was launched for your 1948 product year. In standard driving, the Dynaflow used only the major gear, counting on the torque multiplication of your torque convertor at reduced speeds. https://gearboxauto86295.buyoutblog.com/34111489/a-simple-key-for-gearbox-auto-unveiled