GM "old-look" transit bus

GM "Old Look" Bus
A restored GM "old look" 5105 coach
Overview
Manufacturer	Yellow Coach (1940-1943) GMC Truck and Bus (1944-1969)
Production	1940-1969
Assembly	Pontiac, Michigan
Body and chassis
Class	Transit bus
Powertrain
Engine	Detroit Diesel 4-71 or 6-71
Transmission	Hydraulic or Manual
Dimensions
Length	25 ft (7.6 m), 28 ft (8.5 m), 30 ft (9.1 m), 33 ft (10 m), 35 ft (11 m), 37.75 ft (11.51 m), 40 ft (12 m), or 41.5 ft (12.6 m)
Width	96 in (2.44 m) or 102 in (2.59 m)
Height	113 in (2.87 m) (roofline)
Chronology
Successor	GM New Look

The GM "old-look" transit bus is a transit bus that was introduced in 1940 by Yellow Coach beginning with the production of the model TG-3201 bus. Yellow Coach was an early bus builder that was partially owned by General Motors (GM) before being purchased outright in 1943 and folded into the GM Truck Division to form the GM Truck & Coach Division. The Yellow Coach badge gave way to the GM nameplate in 1944. Production of most "old-look" models was stopped upon the release of the GM New-Look bus in 1959, however some smaller "old-look" models continued to be built until 1969. Approximately 38,000 "old-look" buses were built during the 29-year production run. The "old-look" name is an unofficial term that was applied to this series of GM buses after the release of the GM New-Look, with "New-Look" being an official term used by GM to describe their new line of buses that superseded the "old-look". This is an example of a retronym.

The GM "old-look" bus was somewhat streamlined in appearance (resembling the PCC streetcar in styling), similar in shape to a loaf of sandwich bread, and had windows that were smaller than those found on more modern bus designs produced after the 1950s. Unlike most earlier buses, the GM "old-look" bus was built using a monocoque design, rather than a body-on-frame design, and it helped shepherd the change from gasoline to diesel-powered buses. Most "old-look" buses were powered with the Detroit Diesel 6-71 inline six-cylinder diesel engine, the exceptions being the shorter models that were powered by the four-cylinder version of the same diesel engine, and buses that were equipped with gasoline engines. Manual and automatic transmissions were available, with the Spicer angle-drive two-speed transmission being used on automatic-equipped buses built prior to 1948. After 1948, the 2-speed Allison V-drive transmission was used on automatic-equipped buses. In 1940 and 1942, a small number of buses were built with electric propulsion systems instead of a transmission. The "old-look" was available in several lengths ranging from 25 feet (7.6 m) to 41 feet 6 inches (12.65 m), though the most common models were 35 feet (11 m) and 40 feet (12 m) feet long. Most "old-look" buses were 96 inches (2.4 m) wide, but 102-inch-wide (2.6 m) models were available beginning in 1948. In 1946 GM began offering its Thermo-matic heating and ventilation system, and in 1952 started making suburban models (identifiable by larger passenger windows, and equipped with high-backed forward-facing seats and optional luggage racks). Beginning in 1953, air-ride suspension became standard on all but the smallest model buses, and in 1958, air conditioning was added as an available option.