The C/K is a series of trucks that General Motors manufactured from the 1960 to 2002 model years and sold through both Chevrolet and GMC dealers. Most people know it as a pickup, but the line also included chassis-cab and medium-duty trucks and served as the basis for GM’s full-size SUVs.
GMC C/K at a glance
| Production | 1960-2002 model years |
|---|---|
| Sold by | Chevrolet and GMC |
| Meaning | C = two-wheel drive, K = four-wheel drive |
| First generation | 1960-1966 |
| Second generation | Action Line, 1967-1972 |
| Third generation | Rounded Line, 1973-1991 |
| Fourth generation | 1992-2002, GMC-badged as the Sierra |
| GMC nameplates | Sierra from 1972, the only nameplate from the fourth generation |
| Chassis | drop-centre frame, independent front suspension, coil-sprung rear axle |
| Notable firsts | four-door crew cab; dual rear wheels; diesel engine in 1978 |
| Medium-duty successor | GMC TopKick, from 1990 |
| Also built in | Argentina, Brazil and Chile |
Based on one source, the English Wikipedia article on the Chevrolet C/K, which covers the trucks GMC sold under the same internal code.
History of the GMC C/K
First generation (1960-1966)
Launched in the autumn of 1959 as a 1960 model, the first C/K replaced the Task Force range and was developed from the start as a truck chassis rather than sharing the GM A-body platform. It still borrowed car features to make it more useful: a drop-centre frame allowed a lower cab and a lower centre of gravity, and independent front suspension was paired with a coil-sprung rear axle. The C/K name was developed by GMC, with C standing for conventional cab and K for four-wheel drive. There was no comprehensive facelift, only a series of gradual changes: a redesigned hood for 1962 and a new windscreen and A-pillar for 1964.
Second generation (1967-1972)
Introduced for 1967 and designated the Action Line by GM, the second generation carried over the drop-centre ladder frame and coil-sprung rear axle but had an entirely new body, designed to work as a multi-purpose vehicle. Alongside its utility role it could be ordered with features from Chevrolet sedans, including automatic transmission, AM/FM radio, carpet and two-tone paint. A big-block V8 was offered for the first time in 1968, and after 1969 GM used only Chevrolet-built engines in C/K pickups. The Chevrolet Cheyenne nameplate appeared in 1971 and the GMC Sierra in 1972. The Action Line also provided the basis for the K5 Blazer and the Suburban.
Third generation (1973-1991)
The Rounded Line generation of 1973 grew inside and out as pickups became personal vehicles, with power windows and door locks on the options list. A four-door crew cab with six seats was introduced, and so was a dual rear-wheel pickup known as the Big Dooley. The trucks were the first C/K generation designed with computers and wind tunnels, and the chassis was all new with leaf springs at the rear; K-series trucks moved to all-wheel drive, with shift-on-the-fly four-wheel drive from 1981. For 1978 the C/K became the first American full-size pickup offered with a diesel, the 5.7 L Oldsmobile V8.
Fourth generation and the end
For the fourth generation Chevrolet kept the C/K designation while GMC changed its branding to the single Sierra nameplate, although C/K remained the internal code. In 1990 the medium-duty C/K trucks were replaced by the GMC TopKick and Chevrolet Kodiak, and for 1999 GM replaced the fourth-generation pickups with an all-new line, with Chevrolet adopting the Silverado name. The last C/K pickups were built for the 2000 model year, and the final medium-duty chassis-cab trucks for the US market in 2001 and 2002. The C3500HD stayed in production for Mexico until 2006. The line was also built in Argentina from 1960 to 1978 and in Brazil for Brazil, Argentina and Chile from 1964 to 2001.
Design and features
- Two drive layouts: C for two-wheel drive and K for four-wheel drive, used as both name and model code.
- Drop-centre frame: a lower cab and centre of gravity than a conventional truck frame allowed.
- Car-like options: automatic transmission, radio, carpet and two-tone paint from the Action Line onwards.
- Crew cab and dual wheels: both arrived with the Rounded Line generation.
- Diesel first: the 1978 C/K was the first American full-size pickup with a diesel engine.
GMC C/K versions
- First generation (1960-1966): the original C/K with independent front suspension.
- Action Line (1967-1972): the second generation, with the Sierra name from 1972.
- Rounded Line (1973-1991): the square-body generation with crew cab and dual rear wheels.
- Fourth generation (1992-2002): sold by GMC as the Sierra.
- Medium-duty C/K: chassis-cab and medium-duty models replaced by the TopKick in 1990.
The C/K was the basis of the GMC Blazer and the GMC Suburban, and its fourth generation carried the Sierra name. Its medium-duty successor was the GMC TopKick. More trucks are in the GMC collection.
Sources
- Chevrolet C/K, English Wikipedia: generations, dates, chassis, nameplates, production outside the US
