The 1st automatic transmission to work with a torque converter (as an alternative to a fluid coupling) was the Buick Dynaflow, which was launched for your 1948 design 12 months. In regular driving, the Dynaflow utilised only the top gear, relying on the torque multiplication in the torque convertor at https://gearbox-auto65308.blogdomago.com/32712879/gearbox-auto-fundamentals-explained