Vtg Tool Check Brass Tag: GM DETROIT TRANSMISSION (Became Hydra-Matic Division)
1-1/8"
General Motors created the Detroit Transmission Division in the late 1930s to build its brand-new automatic shifting system. They named the landmark gearbox Hydra-Matic. Because the transmission became so famous, GM officially changed the factory name to the Hydra-Matic Division on October 1, 1963