Look on the transmission case to locate a Chevy transmission serial number. The numbers are usually located on the transmission housing's middle to lower side, although the exact locations of the numbers vary depending on the application. Every cylinder block and transmission of most late model Chevrolets have vehicle identification numbers and serial numbers stamped on them. The VIN is the same as the instrument panel's stamped vehicle serial number but without the four digits indicating body style.
A Chevrolet serial number may be located on the transmission's passenger side, just above the pan. The most important digit is the first one, which indicates the year the company manufactured the transmission.
Chevrolet paired various transmissions to its full-size engines over the years, such as the Power Glide transmission in 1979 to 1980. The automaker used several Turbo Hydramatic transmissions between 1979 and 1989, including the Turbo Hydramatic 200 and 350 from 1979 to 1981, the 200C from 1982 to 1986 and the Hydramatic 200-4R overdrive four-speed from 1979 to 1989.
An automotive engine creates power, or torque, and sends it to the automatic transmission, which sends it to the differential. The transmission contains sets of gears that change automatically, depending on driving conditions and vehicle speed. The gear changes maintain the engine's efficient operation.