GM New Look Bus - Description

Description

Like GM's over-the-road buses, including the Greyhound Scenicruiser, the air-sprung New Look did not have a traditional ladder frame. Instead it used an airplane-like stressed-skin construction in which an aluminum riveted skin supported the weight of the bus. The wooden floor kept the bus' shape. The engine cradle was hung off the back of the roof. As a result, the GM New Look weighed significantly less than competitors' city buses.

Virtually all New Look buses were powered by Detroit Diesel 71-series two-cycle Diesel engines. The original engine was the 6V71 (V6). GM buses used a unique "Angle-drive" configuration with a transverse mounted engine. The transmission angled off at a 45-or-so degree angle to connect to the rear axle. The engines were canted backwards for maintenance access; in fact, the only parts not accessible from outside the bus were the right-hand exhaust manifold and the starter. The entire engine-transmission-radiator assembly was mounted on a cradle that could be quickly removed and replaced, allowing the bus to return to service with minimal delay when the powertrain required major maintenance. Originally, all New Looks were powered by the 6V-71. GM resisted V8 power but eventually gave in to pressure from customers.

(The exception to the above was the 29-foot (8.84 m) TDH-3301, which was powered by the GMC DH-478 Toroflow four-stroke V6, and had a more conventional T-drive transmission.)

Original transmission choices were a four-speed non-synchronized manual transmission with solenoid reverse and the Allison Automatic VH hydraulic transmission. The latter was essentially a one-speed automatic transmission which drove the wheels through a torque converter. At sufficient speed a clutch bypassed the torque converter and the engine drove the rear wheels directly. A later option was the VS-2, similar to the VH but with a two-speed planetary gearset with three modes: Hydraulic, direct (1:1), and direct-overdrive. The very last batch of American-built New Looks and most Canadian-built New Looks from 1977 through 1987 use the Allison V730 transmission, a traditional three-speed automatic with a lockup torque converter. These four transmissions were the only V-drive transmissions made.

New Looks were available in both Transit and Suburban versions. Transits were traditional city buses with two doors; Suburbans had forward-facing seats (four-abreast), underfloor luggage bays, and had only one door. The center aisle of the Suburbans was lower than the floor beneath the seats, to accommodate the luggage bays. There were also "Suburban-style" transits which had forward-facing seats on slightly raised platforms that gave the appearance of a dropped center aisle. GM refused to install lavatories on its buses; at least one transit authority Sacramento Transit Authority in Sacramento, California added its own.

The New Look was built in 30 ft (9.14 m), 35 ft (10.67 m) and 40 ft (12.19 m) lengths and 96 and 102 in (2.44 and 2.59 m) widths. 35 and 40 ft (10.67 and 12.19 m) buses had different-length side windows, so the profiles of both buses looked very similar, but not the same.