The first automatic transmission to work with a torque converter (rather than a fluid coupling) was the Buick Dynaflow, which was released with the 1948 product 12 months. In typical driving, the Dynaflow employed only the top gear, counting on the torque multiplication of your torque convertor at decrease speeds. https://gearbox-auto76318.blogpayz.com/33864158/the-basic-principles-of-gearbox-auto