The first automatic transmission to implement a torque converter (rather than a fluid coupling) was the Buick Dynaflow, which was introduced for your 1948 model calendar year. In standard driving, the Dynaflow employed just the top rated equipment, depending on the torque multiplication from the torque convertor at lower speeds. https://gearboxauto09740.blogcudinti.com/34248084/gearbox-auto-for-dummies