The 1st automatic transmission to use a torque converter (rather than a fluid coupling) was the Buick Dynaflow, which was launched to the 1948 model year. In standard driving, the Dynaflow used only the top equipment, counting on the torque multiplication from the torque convertor at lower speeds. The Dynaflow https://gearboxauto34678.vblogetin.com/39499320/gearbox-auto-an-overview