|This article needs additional citations for verification. (May 2014)|
Restored CCKW 353 Cargo truck with open cab, machine gun ring,
and front-mounted winch
|Type||2 1⁄2 ton (2,268kg)[a] 6x6 Cargo truck|
|Place of origin||United States|
|Manufacturer||Yellow Coach/GM Truck and Coach|
|Variants||Various (See text)|
|Specifications (353 Cargo w/winch)|
|Weight||8,800 lb (4,000 kg) empty
16,400 lb (7,400 kg) loaded
|Length||270 1⁄8 in (6.86 m)|
|Width||88 in (2.24 m)|
|Height||93 in (2.36 m) to cab
109 1⁄8 in (2.77 m) overall
91 hp (68 kW)
|Transmission||5 spd. x 2 range trf. case|
|Suspension||Beam axles on leaf springs|
|300 mi (482.8 km)|
|Speed||45 mph (72 km/h)|
Thе GMC CCKW is a 2 1⁄2 ton 6X6 U.S. Army cargo truck that saw service in World War II and the Korean War, often referred to as a "Deuce and a Half" or "Jimmy". The CCKW came in many variants, based on the open or closed cab, and Long Wheel Base (LWB 353) or Short Wheel Base (SWB 352).
CCKWs were employed in large numbers for the Red Ball Express, an enormous convoy system created by the Allies to supply their forces moving through Europe. At its peak, the Red Ball operated 5,958 vehicles, and carried about 12,500 tons of supplies a day.
- "C", designed in 1941
- "C", conventional cab
- "K", all-wheel drive
- "W", dual rear axles
Including the DUKW, General Motors in the US produced 562,750 of these 2 1⁄2 ton (2,268kg) trucks just prior to and during World War II.
In 1940, the US Army set a requirement for a 6x6 truck with a 12 ft (3.7 m) cargo area and a 2 1⁄2 ton (2,268 kg) off-road payload. General Motors, already supplying modified commercial trucks to the Army, modified the 1939 ACKWX-built for the French Army-into the CCKW. The General Motors design was chosen by the Army.
In 1942, GM’s Yellow Truck and Coach began building CCKWs and 6x4 CCWs. They were produced in Pontiac, Michigan and later at the St. Louis, Missouri Chevrolet plant. In 1943, Yellow became GM Truck and Coach Division, hence the name GMC ( affectionately known as "Jimmys"). By the end of production in 1945, 562,750 CCKWs had been built, a total second only to the “Jeep”.  
Engine and driveline
The CCKW was equipped with the GMC 270 engine, an overhead valve I6 with 91 hp (68 kW) at 2750rpm and 216 lbf·ft (293 N·m) at 1400rpm. A 3 25⁄32 in (96 mm) bore by 4 in (102 mm) stroke gave a 269.5 cu in (4.4 L) displacement. This engine was designed for commercial trucks, and proved reliable in service.
The transmission was a Warner T93 5-speed with a direct 4th gear and overdrive 5th gear. The transfer case had high and low gears, and engaged the front axle. Originally all axles were a Timken split type, later trucks also used GM "banjo" types.
The CCKW had a ladder frame chassis with three driven beam axles, the front on semi elliptical leaf springs, the rear tandem on quarter elliptical leaf springs with locating arms. There were two wheelbases, the short Model 352 and the long Model 353. The short, 145 in (368 cm) / 167 in (424 cm)[b], was used with a short cargo bed as an artillery prime mover for 75mm and 105mm howitzers. All other models used the long, 164 in (417 cm) / 186 in (472 cm).[b] Tires were 7.50-20, brakes were hydraulic with vacuum assist.
Some were fitted with 10,000 lb (4,500 kg) front-mounted winches. These used longer frame rails, and could only be installed at the factory, rather than in the field.
Initially, all versions used a modified commercial closed cab design having a metal roof and doors. By 1944 an open cab version, with a canvas roof and doors, was used. This was easier to build, and the roof could be removed to lower the shipping height. 1 in 4 open cabs had a machine gun mounting ring above the co-drivers position.
The CCKW provided a platform for the widest range of bodies on any U.S. military vehicle, with the 12 ft (3.7 m) cargo version being the most common. As steel was more heavily rationed during the course of the war, the steel cargo bed was replaced by a wooden one. Wooden beds proved unsatisfactory and a 'composite' bed with steel sides, framing, and wooden bottom slats was developed. However, the composite bed was still unsatisfactory and the bed design returned to all steel.
In addition to the two major types, many other bodies were built in smaller numbers, and others were converted in the field. These include:
- Truck, cargo, 2½-Ton, 6X6, long-wheelbase / short-wheelbase
- Bomb Service
- Chemical decontaminating
- Chemical handling
- Dental Operating Van
- Fire Engine
- Fuel tanker (750 US gal (2,800 l))
- High lift
- K-53 Van
- K-60 Van
- Ordnance Maintenance Van
- Pipeline equipment
- Pontoon bolster
- Surgical Van
- Water purification truck
- Water tanker (700 US gal (2,600 l))
The AFKWX[d] 353 also went into production alongside the CCKW in 1942 at Yellow’s Pontiac plant and Chevrolet’s in St. Louis. Mechanically identical to the CCKW, it had a cab over engine design, allowing a 15 ft (4.6 m), and later 17 ft (5.2 m) long cargo bed. The first 50 produced had closed cabs, and all others featured open ones. Only cargo beds were equipped, and none had a front-mounted winch. The COE design made engine maintenance difficult. A largely unsuccessful design, just 7235 were built.
The DUKW[e] “Duck” was an amphibious truck that shared the CCKW's driveline. First produced at Yellow’s Pontiac plant, as demand increased production was added to Chevrolet’s St. Louis plant. The hull, designed by an America's Cup winner, had excellent sea-keeping abilities. This was a very successful design; 21147 were built.
- List of U.S. military vehicles by supply catalog designation (G508)
- List of U.S. military vehicles by model number
- List of U.S. Signal Corps Vehicles
- General Motors
- M35 2½ ton cargo truck
- Chevrolet G506 trucks
- Studebaker US6
- 17th Armored Engineer Battalion
- Off-road load rating
- Measurements are from the centerline of the front axle to the centerline of rear bogie / rear axle.
- GM name: C for 1941, C for conventional cab, and W for tandem rear axles.
- GM name: A for 1939, F for forward cab, K for all wheel drive, and W for tandem rear axles.
- GM name: D for 1942, U for utility, K for all wheel drive, and W for tandem rear axles.
- "TM-9-801 2 1⁄2 ton 6x6 GMC CCKW". US War Dept. 24 Apr 1944. pp. 6–9, 16–19. Retrieved 20 Dec 2014.
- David P. Colley (2000). The Road to Victory: The Untold Story of World War II's Red Ball Express. Potomac Books. ISBN 1-57488-173-6.
-  The Real History of World War II: A New Look at the Past by Alan Axelrod, Sterling Publishing Company, Inc., 2008, ISBN 1-4027-4090-5, ISBN 978-1-4027-4090-9
- Crismon, Fred W (2001). US Military Wheeled Vehicles (3 ed.). Victory WWII Pub. pp. 184, 326, 330–335, 465. ISBN 0-970056-71-0.
- Doyle, David (2003). Standard catalog of U.S. Military Vehicles. Kraus Publications. pp. 108–118. ISBN 0-87349-508-X.
- Ware, Pat (2010). The World Encyclopedia of Military Vehicles. Lorenz Books. pp. 238–239. ISBN 0-7548-2052-1.
- "TM-9-2800 1943 Standard Military Motor Vehicles". US Dept. of the Army. 1 Sep 1943. pp. 238–276. Retrieved 1 Dec 2014.
|Wikimedia Commons has media related to GMC CCKW.|
- "GMC trucks at The-Blueprints.com". Onno van Braam. 2014. Retrieved 5 Oct 2014.