The GMC General is a heavy-duty Class 8 truck that the GMC Truck and Coach Division of General Motors assembled from 1977 to 1987. It was the largest conventional-cab truck the company ever produced and replaced the Chevrolet and GMC C/M 90 and 9500 trucks.
GMC General at a glance
| Class | Class 8 heavy-duty conventional |
|---|---|
| Production | 1977-1987 |
| Also sold as | Chevrolet Bison, 1977-1980 |
| Replaced | Chevrolet/GMC C/M 90 and 9500 |
| Assembled | Pontiac Central Assembly, Pontiac, Michigan |
| Cab | all-aluminium cab built by Budd |
| Hood options | 108 in or 116 in bumper to back of cab |
| Cab types | day cab, 34 in sleeper, walk-in sleeper from 1985 |
| Standard engine | Detroit Diesel 6-71, later 6V92 |
| Other engines | Cummins N-series, Detroit 8V71 and 8V92, Caterpillar 3406 from 1982 |
| Fuel | diesel only, no petrol engines |
| Final truck | 1987 |
Based on one source, the English Wikipedia article on the GMC General.
History of the GMC General
From the C/M series
In 1966 GMC Truck and Coach introduced its first dedicated heavy-duty trucks, moving away from models adapted from the smaller C/K line. The division brought out two lines sharing a cab: the H/J series with a 93-inch bumper-to-back-of-cab dimension and the C/M series with 112 inches. The C/M trucks had a longer hood to take larger diesels such as the Cummins NH and V903 and the Detroit Diesel 8V71, and a front-hinged fibreglass hood replaced the centre-hinged butterfly hood of the H/J. After the medium-duty C/K arrived in 1973 the 112-inch truck was consolidated into the M series. During 1977 and 1978 GMC split its heavy range further: the Chevrolet M90 and GMC M9500 were replaced by the Chevrolet Bison and GMC General in 1977, and the H/J range became the Chevrolet Bruin and GMC Brigadier in 1978.
Design
Similar in layout to the Ford LTL-9000, International Harvester Transtar 4300 and Mack Super-Liner, the General and Bison were Class 8 conventionals with an all-aluminium cab built by Budd, available in many combinations. Two hood configurations were offered, 108-inch and 116-inch bumper-to-back-of-cab, and buyers could choose a day cab, a 34-inch sleeper or, from 1985, a walk-in sleeper. No petrol engines were available. The Detroit Diesel 6-71 was standard and was later replaced by the 6V92, while the Cummins N-series, Detroit 8V71 and 8V92 could be specified and the Caterpillar 3406, already used in the GMC Astro, joined the list in 1982.
Glider trucks
When the Bison and General were introduced in 1977 they were available from dealers as vehicle gliders: essentially complete trucks without engine, transmission and rear axles. The incomplete vehicles served two purposes, either to take an existing powertrain into a new truck or to allow customisation that a dealership could not offer.
Discontinuation
The General quickly overtook the Chevrolet Bison in sales. In 1981 Chevrolet ended heavy truck sales altogether, cancelling the Bruin, Bison and Titan, largely because Chevrolet dealers lacked the product support. GMC franchisees, by contrast, were required to sell and service the entire GMC line, including medium and heavy trucks, the Motorhome, P-chassis and bus chassis. In 1986 Volvo took an 85 percent stake in a heavy-truck joint venture with GM, trading as Volvo GM Heavy Truck Corporation under the WhiteGMC badge, and GMC trucks were phased out in favour of White designs. The last GMC General was built in 1987, followed by the Brigadier in 1988 as a WhiteGMC, which marked GM’s exit from the Class 8 segment.
Design and features
- All-aluminium cab: a Budd-built cab shared with the Chevrolet Bison.
- Two hood lengths: 108-inch or 116-inch bumper-to-back-of-cab configurations.
- Sleeper options: a 34-inch sleeper from launch and a walk-in sleeper from 1985.
- Diesel only: Detroit Diesel, Cummins and Caterpillar engines, no petrol option.
- Glider availability: trucks could be bought without engine, transmission and rear axles.
GMC General versions
- GMC General (1977-1987): the GMC-badged Class 8 conventional.
- Chevrolet Bison (1977-1980): the same truck sold by Chevrolet dealers.
- Day cab and 34-inch sleeper: the two original cab layouts.
- Walk-in sleeper (1985): the later high-roof sleeper option.
- Glider: a complete truck supplied without its powertrain.
The General was the largest stablemate of the GMC Brigadier and the cabover GMC Astro, and its role was later taken by the TopKick in the medium-duty range. More trucks are in the GMC collection.
Sources
- GMC General, English Wikipedia: background, design, engines, discontinuation
