M809 series 5-ton 6x6 truck

M809 Series 5-ton 6x6 Truck
M813 crossing a river
Type	5-ton 6x6 trucks
Place of origin	United States
Production history
Manufacturer	AM General
Produced	1970–1982
Specifications (M813 with winch)
Weight	21,020 lb (9,530 kg) (empty)
Length	26 ft 7 in (8.10 m)
Width	8 ft 2 in (2.49 m)
Height	9 ft 9 in (2.97 m)
Engine	Cummins NH250 240 hp (180 kW)
Transmission	5 speed x 2 range
Suspension	Live beam axles on leaf springs
Operational range	350 mi (563.3 km)
Speed	52 mph (84 km/h)

The M809 Series 5-ton 6x6 truck (G908) was a family of heavy tactical trucks built for the United States Armed Forces. The basic cargo version was designed to transport a 5-ton (4,500 kg), 14 ft (4.3 m) long load over all terrain in all weather. In on-road service the load weight was doubled. Built by AM General, they evolved into the M939 Series.

In the late 1960s the US Army needed more 5-ton (4,536 kg) 6x6 trucks. Kaiser-Jeep developed an updated version of the M39 series which had been in service since 1951. The primary difference was the engine change to Cummins. The hood and grille were lengthened to make room for the longer engine and the lighting system was updated to meet new US safety regulations. All had an air cleaner on the left fender, a way to tell them from the earlier M39 series.

Kaiser-Jeep was awarded the M809-series contract DAAE06-69-C-0009 and built them during 1969 and into 1970. In February 1970, Kaiser-Jeep was purchased by American Motors Corporation and on March 26, 1970, Kaiser-Jeep was reorganized as the "Jeep Corporation." The South Bend facilities where the M809-series was being built subsequently became Jeep Corporation's "General Products Division." Just over a year later, on March 31, 1971, this General Products Division was spun off and became "AM-General," a wholly owned subsidiary of American Motors Corporation. In 1974, a new contract for the M809-series was awarded to AM General, DAAE07-74-C-0120. This contract covered trucks built over the next 5 years at least. AM-General built all M809-series trucks between 1971 and 1982. In 1982, the M809-series was then improved into the M939 series. The first 11,000 M939s were rebuilds of M809s.

The M809 series used a Cummins NHC250 engine, a 855 cu in (14.0 L) naturally aspirated inline 6 cylinder diesel engine developing 240 hp (180 kW) at 2100rpm and 685 lbf·ft (929 N·m) of torque at 1500rpm. All models of the M809 series used this engine throughout their service life. The N series was a successful commercial design, with a conservative rating the engine was more powerful and less stressed than the Continental LDS-465 multifuel engine used in the M39 series.