The very first automatic transmission to utilize a torque converter (in place of a fluid coupling) was the Buick Dynaflow, which was released for your 1948 design year. In regular driving, the Dynaflow utilized just the major equipment, counting on the torque multiplication from the torque convertor at lower speeds. https://daltonwgllk.bloguetechno.com/top-latest-five-gearbox-auto-urban-news-69247797