The main automatic transmission to implement a torque converter (in lieu of a fluid coupling) was the Buick Dynaflow, which was released for that 1948 model 12 months. In regular driving, the Dynaflow used only the major gear, counting on the torque multiplication with the torque convertor at lower speeds. https://gearbox-auto96394.articlesblogger.com/56626472/how-much-you-need-to-expect-you-ll-pay-for-a-good-gearbox-auto