The M35 2½-ton cargo truck is a long-lived vehicle initially deployed by the United States Army, and subsequently utilized by many nations around the world. A truck in the 2½ ton weight class, it was one of many vehicles in U.S. military service to have been referred to as the “deuce and a half.” While the basic M35 cargo truck is rated to carry 5,000 pounds (2,300 kg) off road or 10,000 pounds (4,500 kg) on roads, they have been known to haul twice as much as rated. Trucks in this weight class are considered medium duty by the military and Department of Transportation. The M35 series formed the basis for a wide range of specialized vehicles.
Design and development
The M35 started out in 1949 as a design by the REO Motor Car Company as a 2 1/2 ton three axle all wheel drive off road truck that was later nicknamed the “deuce and a half”. The first vehicle in the family, the M34, was quickly superseded in military usage by the M35, the major difference being the M35’s 10-tire configuration versus the M34’s 6-tire configuration.
An M35A2 cargo truck with winch is 112 inches (2.8 m) tall, 96 inches (2.4 m) wide and 277 inches (7.0 m) long, and 15,030 pounds (6,820 kg) empty (15,530 pounds (7,040 kg) empty when equipped with the front mount winch, according to dashboard data plates). The standard wheelbase cargo bed is 8 feet by 12 feet (2.4 x 3.6 m). The M35A2 was available with a canvas soft top, as pictured, or a metal hard top. Metal hard-top configurations are most often found on vehicles that have been equipped with cold-weather gear, including additional insulation in the cab, as well as enginecoolant or multifuel-fired cab personnel heaters.
The M35A2 is popularly powered by an LDT 465 engine, made by either Continental Motors Company, Hercules, or White Motor Company. It is an in-line, 478-cubic-inch (7.8 L), six-cylinder, turbocharged multifuel engine developing 134 bhp (100 kW) and 330 pound force-feet (447 N·m) of torque. This is coupled with a 5-speed manual transmission and divorced 2-speed transfer case (either a sprag-operated transfer case Rockwell 136-21 or air-operated selectable transfer case Rockwell 136-27). Multifuel engines are designed to operate reliably on a wide variety of fuels, to include diesel fuel, jet fuel, kerosene, heating oil or gasoline. Gasoline should only be used in an emergency because it does not properly lubricate the injector pump. While using gasoline, common practice calls for the addition of at least 1 U.S. quart of clean motor oil per 15 U.S. gallons of gasoline (1 imp qt/13 imp gal; 1 L/60 L) for proper pump lubrication where available.
Although the A2 version is by far the most common, there are four different iterations: Standard, A1, A2, and A3 iterations. These changes mainly had to do with the engine and transmission components. Standard M35 had a REO “Gold Comet” or Continental OA331 inline-6 gasoline engine. Some had 4-speed transmissions but most had “direct 5th” transmissions. The gasoline-powered deuces were built primarily by REO Motors, however, Studebaker also had a manufacturing contract from at least 1951 up into the early 1960s. Curtis-Wright also had a contract in at least 1958 to build dump trucks with the Continental gas engine. The A1’s had Continental LDS-427-2 turbo engines,equipped with either a model 4-450 Schwitzer turbo, or a 4D454C Schwitzer turbo on later models, and 5th gear was an overdrive. The 140 hp engines were not reliable, suffering frequent headgasket failures. First A2 trucks received the bigger LD-465-1 naturally aspirated 478 CID Multifuel engines, keeping the OD transmission of the A1s. Through the years the trucks were upgraded to LD 465-1c engines, with 60Amp alternator instead of the 25Amp generator. With the addition of a turbo, this engine evolved into the LDT 465-1c (turbo clean air). The turbo was added more to clean up the very black exhaust on the Non Turbo engines, than to add power, the HP was only raised from 130 to 135 HP.Turbo models used: 3LD305(early engines only) and 3LJ319 (the “whistler”) The LDT-465-1D was the last version of the Multi Fuel, it had the same 3LJ319 Turbo(whistler), or the quieter 3LM39 (non-whistler), better head gasket sealing and head cooling.
In 1994 the M35A3 variant was introduced as part of Extended Service Program, and between then and 1999. Usually, A3 vehicles have a Caterpillar 3116 Diesel engine and had their manual transmissions replaced with automatic ones, as well as receiving numerous other improvements and a redesigned frontal appearance. No new A3 standard-transmission vehicles were produced, all vehicles being upgraded from previous configurations.trucks during the rebuild process. The exception to the rule are some M109A3 shop vans, a small number of M109A3s were upgraded to A4 specs using the M35A3 upgrade parts and procedures. As-built original A1’s are gassers, A2’s are LDS 427-2 multifuelers,and A3 are LD/LDT 465-1c multifuelers. however it is still common to find rebuilds of former gas-powered REO and Studebaker models having A1 and A2 multifuel configurations.
The curb weight of an M35 is between 13,000 pounds (5,900 kg) and 16,000 pounds (7,300 kg) empty, depending on configuration (cargo, wrecker, tractor, etc.). Its top speed is 56 mph (90 km/h), though maximum cruising speed is approximately 48 mph (77 km/h). Fuel economy is 11 mpg-US (21 L/100 km; 13 mpg-imp) highway and 8 mpg-US (29 L/100 km; 9.6 mpg-imp) city, giving the deuce a 400-500-mile (600–800 km) range on its 50 U.S. gallons (190 L; 42 imp gal) single fuel tank. On average, most operators experience tank averages of 8–10 mpg-US (29–24 L/100 km; 9.6–12 mpg-imp) for an unladen vehicle.
Brake system is air-assisted-hydraulic six wheel drum with a driveline parking brake, although gladhands exist on the rear of the vehicle for connection to trailers with full air service and emergency brakes. Braking performance of the truck is similar to other power drum brake vehicles of this size. Each drum was designed with maximum efficiency in mind, and individual drums can dissipate up to 12 kilowatts (16 hp) of braking heat. Due to this brake system and GVWR under 26,001 pounds (11,794 kg), the big deuce can be driven without a commercial driver’s license in most states. Even California does NOT require a CDL to operate an M35 on public roads because even though it has three axles and an air-assisted braking system, the maximum gross weight is still under 26,000 lb (12,000 kg), making it eligible for class C on-road driving; and because the primary braking system is hydraulic, not air.
The electrical system is 24 volt, using two 12 volt 6TL-series military grade batteries run in series.
Some deuces are equipped with a 10,000 pounds (4,500 kg) PTO-driven front winch manufactured by Garwood.
information courtesy of Wikipedia