The very first automatic transmission to utilize a torque converter (in lieu of a fluid coupling) was the Buick Dynaflow, which was released with the 1948 model year. In regular driving, the Dynaflow utilized only the best gear, relying on the torque multiplication on the torque convertor at decrease speeds. https://gregoryxywvs.blogtov.com/14285376/a-simple-key-for-gearbox-auto-unveiled