The first automatic transmission to work with a torque converter (in lieu of a fluid coupling) was the Buick Dynaflow, which was launched for that 1948 design yr. In standard driving, the Dynaflow utilised just the best gear, depending on the torque multiplication of the torque convertor at reduced speeds. https://gearbox-auto30752.webdesign96.com/34286294/little-known-facts-about-gearbox-auto