That was accomplished by the Detroit Transmission Division during development of the Model 315 Dual Coupling Hydra-Matic four speed transmission, which was brought to market for 1956 Cadillac, Oldsmobile and Pontiac models with great success. Chevrolet did not have the benefit of Detroit Division's experience in aluminum case casting, and engineering errors were made, exacerbated by a lack of pre-production testing.
That was accomplished through the efforts of the Detroit Transmission Division during the development of the Model 315 Dual Coupling Hydra-Matic four-speed transmission, which was successfully launched for 1956 Cadillac, Oldsmobile, and Pontiac models. Chevrolet, however, did not have access to the Detroit Division's experience in aluminum casting, leading to engineering errors that were compounded by a lack of pre-production testing.