The Saginaw Michigan SM465 is a heavy-duty, four-speed manual transmission built by

General Motors The General Motors Company (GM) is an American Multinational corporation, multinational Automotive industry, automotive manufacturing company headquartered in Detroit, Michigan, United States. It is the largest automaker in the United States and ...

for use in light and medium duty trucks from 1968 to 1991 at the factory in

Muncie, Indiana Muncie ( ) is an incorporated city and the county seat, seat of Delaware County, Indiana, Delaware County, Indiana. Previously known as Buckongahelas Town, named after the legendary Delaware Chief.http://www.delawarecountyhistory.org/history/docs ...

; it was designed to replace the somewhat similar

Muncie SM420 transmission The Muncie SM420 is a heavy duty, four-speed manual transmission that was produced from 1947 to 1967 by General Motors for civilian use in a variety of pickup trucks, buses, dump trucks and heavy equipment. They were used in some military vehicles ...

, which had been in production since just after

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

. The SM465 can be found in

Chevrolet Chevrolet ( ), colloquially referred to as Chevy and formally the Chevrolet Motor Division of General Motors Company, is an American automobile division of the American manufacturer General Motors (GM). Louis Chevrolet (1878–1941) and ous ...

and GMC full-size trucks,

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s, among other models. Some applications beyond one-ton pickup trucks came with larger input shafts. Favored by off-road drivers, the SM465 has a very low first gear suitable for rock-crawling. The SM465 has developed a reputation as a highly durable transmission. For the 1992 model-year, the SM465 was replaced in 3/4- and 1-ton pickup truck applications by the

New Venture Gear 4500 transmission The New Venture Gear 4500, commonly called NV4500, is a 5-speed manual transmission manufactured by New Venture Gear and used in General Motors and Chrysler products from 1991 to 2007. The NV4500 is a very popular 5-speed manual conversion and upg ...

Design

The "SM" in the transmission's designation does not stand for Synchro-Mesh, contrary to popular belief. "SM" stands for "SAGINAW MICHIGAN". GM literature also often referred to this as a CH465, referencing Chevrolet. Gear ratios are: * First - 6.55:1 * Second - 3.58:1 * Third - 1.70:1 * Fourth - 1.00:1 * Reverse - 6.09:1 The SM465 features dual provisions for power take-offs. The 1988-91 versions have an aluminum top with improved shift feel. The 1985 and newer versions utilize a hydraulic clutch release, replacing a mechanical linkage in older versions. A common wear factor in the form of abuse leads to having to manually hold the gear selector in third. There have been three different output shafts for pickup trucks. Early four-wheel drive was a short 10 spline. Later, a 35-spline version was for 2 wheel drive, whereas 4WD units had a 32-spline output shaft. The SM465 was the only manual transmission available for 1988-1991 R/V-series trucks and SUVs.

References

Automobile transmissions General Motors transmissions {{truck-stub

Design

See also

References