The primary automatic transmission to implement a torque converter (as an alternative to a fluid coupling) was the Buick Dynaflow, which was introduced to the 1948 product year. In standard driving, the Dynaflow used only the major gear, depending on the torque multiplication in the torque convertor at lessen speeds. https://gearbox-auto31851.yomoblog.com/40746021/gearbox-auto-can-be-fun-for-anyone