The very first automatic transmission to make use of a torque converter (as opposed to a fluid coupling) was the Buick Dynaflow, which was introduced to the 1948 product 12 months. In typical driving, the Dynaflow used just the prime gear, counting on the torque multiplication on the torque convertor https://israelucfjj.blogmazing.com/33283629/gearbox-auto-an-overview