The main automatic transmission to make use of a torque converter (as an alternative to a fluid coupling) was the Buick Dynaflow, which was released for the 1948 model yr. In regular driving, the Dynaflow made use of only the major gear, depending on the torque multiplication from the torque https://gearbox-auto77520.59bloggers.com/34097623/the-basic-principles-of-gearbox-auto