The initial automatic transmission to utilize a torque converter (as opposed to a fluid coupling) was the Buick Dynaflow, which was introduced for that 1948 product 12 months. In standard driving, the Dynaflow utilized just the leading gear, depending on the torque multiplication on the torque convertor at reduced speeds. https://gearbox-auto21851.wssblogs.com/34088504/considerations-to-know-about-gearbox-auto