US Military M-39 Series 5-ton, 6x6 Trucks (G-744)
Production of the M-39 series of five ton trucks began in 1951, in a rush to meet requirements for the Korean War. By 1953 the trucks had been standardized and the early production by International Harvester, Diamond T, and Mack was replaced by much larger contracts with IH and Kaiser Jeep.
Truck models in the M-39 Series include:
- M39 Truck, Chassis
- M40 Truck, Chassis
- M41 Truck, Cargo
- M51 Truck, Dump
- M52 Truck, Tractor
- M54 Truck, Cargo
- M55 Truck, Cargo, Extra Long Wheel Base (XLWB)
- M61 Truck, Chassis
- M62 Truck, Wrecker, Medium
- M63 Truck, Chassis
- M64 Truck, Cargo Van
- M139 Truck, Chassis
- M139 Truck, Bridging
- M246 Truck, Tractor, Wrecker
- M289 Truck, Missile Launcher
- M291 Truck, Van, Expansible
- M328 Truck, Bridging
- M386 Truck, Missile Launcher
- M543 Truck, Wrecker, Medium
- M748 Truck, Bolster (or Logging)
Variants with a suffix (e.g. M54A2 or M291A1D) have modifications from an earlier base model (e.g. M54 or M291D), as further explained below. Photos and additional information about many of the M-39 series trucks are on the pages linked from the list above.
There were three wheelbase configurations for the M39 series trucks:
- Standard: 179 inches
- Long: 215 inches
- Dump Truck: 167 inches
The M-39 series trucks were 98 inches wide with typical cab height of 121 inches (soft top erected). The length varied with the wheelbase and body type.
The cab design of the M-39 series five ton trucks was shared with the M-35 series 2 1/2 ton trucks, so both have a very similar look. However, the M-39 series have two fuel tanks, one on each side, while the M-35 series have only a passenger side tank. The M41 Cargo Truck had single rear wheels with 14:00x20 tires as opposed to the M54 Cargo Truck with its 11:00x20 tires and duals on the rear axles. Both had the standard wheelbase of 179 inches. The steel cab with steel doors had a canvas top -- with the top removed and the windshield folded, the height was considerably reduced.
Manuals for the M-39 series of trucks were first produced before the modern system of manual numbering was introduced. The manual for Operation and Organizational Maintenance was originally TM 9-837 (June 1951) which was then replaced by TM 9-8028 (June 1955). Manuals from the new system will be numbered TM 9-2320-211-xx where the xx represents the maintenance level. All together there are dozens of multi-volume manuals for the series of trucks.
M39 Series Evolution
As the M39-series vehicles evolved, the engine and other aspects of the basic configuration were improved. This table applies to most of the trucks in the M-39 series and will be indicated by their A-level suffix (e.g. A1 or A2). All models had a two speed transfer case and air-assisted hydraulic brakes.
| M39 | M39A1 | M39A2 | |
|---|---|---|---|
| Engine Type (6 cal) | Continental R6602 Gasoline | Mack ENDT-673 Diesel | LDS-465-1A Turbo Multifuel |
| Engine Horsepower | 224@2800rpm | 210@2100rpm | 205@2600 |
| Engine Torque | 504 lb-ft | 610 lb-ft | 425 lb-ft |
| Transmission | Spicer 6352 5spd manual | Spicer 6453 5spd manual | Spicer 6453 5spd manual |
The engine air intake of M-39 series vehicles is mounted on the right front (passenger side) fender, the opposite of the M-809 series trucks.
The M-39 series trucks were superseded by the M-809 series of 5 ton trucks, but both types of trucks continued to be used for many years.
