The primary automatic transmission to use a torque converter (as opposed to a fluid coupling) was the Buick Dynaflow, which was launched to the 1948 design 12 months. In usual driving, the Dynaflow used only the prime equipment, relying on the torque multiplication of the torque convertor at lessen speeds. https://gearboxauto64297.ltfblog.com/33089364/detailed-notes-on-gearbox-auto