The 1st automatic transmission to work with a torque converter (as opposed to a fluid coupling) was the Buick Dynaflow, which was introduced with the 1948 design year. In ordinary driving, the Dynaflow utilised only the major gear, relying on the torque multiplication of the torque convertor at decrease speeds. https://stephencgecz.oblogation.com/33319041/gearbox-auto-can-be-fun-for-anyone