The initial automatic transmission to work with a torque converter (as opposed to a fluid coupling) was the Buick Dynaflow, which was launched for that 1948 product calendar year. In ordinary driving, the Dynaflow made use of only the major gear, counting on the torque multiplication from the torque convertor https://gearbox-auto41738.fitnell.com/74928684/a-review-of-gearbox-auto