The 1st automatic transmission to employ a torque converter (in place of a fluid coupling) was the Buick Dynaflow, which was released for that 1948 model 12 months. In standard driving, the Dynaflow used just the prime gear, relying on the torque multiplication from the torque convertor at lower speeds. https://gearboxauto85306.ziblogs.com/33899494/the-fact-about-gearbox-auto-that-no-one-is-suggesting