This has been a discussion of the Hydra-Matic transmission in Chevrolet trucks. GMC Hydra-Matic history differs from Chevrolet.
GMC started using the Hydra-Matic transmission in domestic (non-Military) trucks in one 1952 model (150-22, 3/3 ton delivery/step van) and in all small GMCs (1/2-1 ton) in 1953, and some real interesting Hydra-Matics in big GMCs in 1954.
