The primary automatic transmission to work with a torque converter (in place of a fluid coupling) was the Buick Dynaflow, which was launched for that 1948 design yr. In typical driving, the Dynaflow employed only the top equipment, depending on the torque multiplication on the torque convertor at reduce speeds. https://charliejqsss.boyblogguide.com/33156418/gearbox-auto-fundamentals-explained