Willys MB and Ford GPW World War II Jeeps
The Willys MB or Ford GPW army jeep is the one most people think of when talking about military jeeps. It is known by many names, such as the Willys Jeep, the GI Jeep, the World War II jeep, or just plain Army jeep. This jeep resulted from a design competition that involved American Bantam, Willys-Overland, and Ford. Willys was chosen for the first mass production contract based on the Willys MA design, but the Willys MB which followed incorporated superior features from the Bantam BRC-40 and the Ford GP in addition the the Willys MA. When the War Department realized that hundreds of thousands of jeeps would be needed for World War II requirements, Ford was given a contract to produce the Willys MB design. Ford produced jeeps were designated GPW.
Early Willys MB with slat grill, Australia, 1942.
The Willys MB or Ford GPW jeep of World War II were externally visually the same but with many small differences in production details. The main component that distinguished a Willys-Overland MB from the Ford-built GPW is the tubular front frame cross-member on the MB as opposed to the inverted U-shaped cross-member on the GPW. A visible sign is that GPWs with Ford frames, unlike MBs or GPWs with Willys frames, had holes in the front bumper in line with the frame rails and also had holes in the rear cross member just out from the bumperettes. Many other differences are revealed on this page. [Thanks to Tom Wolboldt for help with GPW ID.]
The early production Willys MB jeeps, about 25,800 of them, had a grill made of vertical welded slats (called the "slat grill" type, photo right) and had "Willys" embossed in the back panel among other small differences. When Ford began producing the nearly identical GPW (with Ford on the back panel) in January-February of 1942, they used the now-standard, less expensive stamped steel slotted jeep grill (photo above, left). The Army wanted full parts interchangability and worked with Ford and Willys to get one standard design for both jeeps -- the Ford idea for the grill was better, so Willys changed over to the stamped grill by April 1942. The Army also insisted that both Willys and Ford drop the embossed company name from the jeep exterior.
World War II Production of Military Jeeps
At the outset, all engines were produced by Willys but in 1942 Ford began to produce GPW engines to the Willys design. Midland Steel Corp. produced frames to the Willys specification and wre used by both Willys and For. Ford contracted with Murray Corp. for frames for the GPW after which Ford no longer used the Midland frames. During 1941 to 1943 Willys and Ford manufactured their own bodies, slightly different from each other. In early 1944, both Willys and Ford subcontracted their jeep bodies to American Central Body of Connersville, IN, who built the so-called "composite body" used by both manufacturers.
After about 25,000 units were produced, in early 1942 the MB/GPW was standardized with changes agreed upon by Ford, Willys and the Army. The 1941 and early 1942 production jeeps have many small differences from the later, full production models. The most visible change was the Ford nine-slot stamped grill which replaced the Willys slat grill (similar to the Ford GP) in March-April 1942.
Ford's River Rouge plant produced the first 77 GPWs with Willys engines and Midland frames in January 1942. Willys jeeps were produced in their Toledo, OH plant, while Ford had assembly operations at six plants around the country. Although small differences remained, the MB and GPW essentially met the Army's goal of being completely interchangeable in all parts. At the factories, there were Ford GPWs produced on Willys Midland frames or with Willys engines, plus other production expedients and subcontractor sharing, creating a mix of jeeps and parts to be sorted out by later generations.
During the course of the war, Ford built 277,896 GPW jeeps, and Willys built 335,531 units. Production contracts were terminated in the summer of 1945 as World War II ended. The last Ford GPW was built on 30 July 1945 and the last Willys MB rolled off the Toledo assembly line on 20 August 1945.
Specifications of the Willys MB / Ford GPW Military Jeep
| Length | 132.25 inches |
| Width | 62 inches |
| Height, top up | 69.75 inches |
| Height, top down | 52 inches |
| Engine | Willys or Ford 4 cyl L-head, 134.2 ci, 6.48:1 compression |
| Horsepower (net) | 54 @ 4,000 rpm |
| Transmission | Warner T-84J 3 speed synchromesh |
| Transfer case | Dana Spicer 18 2 speed |
| Gear Shift | Floor mounted |
| Axles | Spicer Dana 4.88:1 23-2 rear, Dana 25 front |
| Electrical System | 6v, neg ground |
| Wheelbase | 80 inches |
| Ground Clearance | 8.75 inches |
| Approach Angle | 45° |
| Departure Angle | 35° |
| Weight w/o gas and water | 2,337 lbs |
| Fording Depth | 21 inches max |
| Tires | 6.00x16 non-directional |
Tabulated data from TM9-803, February 1944. All Willys MB and Ford GPW jeeps have a serial number tag on the left front of the frame. The serial number appears in other locations and there is also a non-matching engine number.
Recommended Books about the Willys MB / Ford GPW
- All American Wonder, Vol I
- All American Wonder, Vol II
- All American Wonder, Vol III
- Jeeps 1941-45
- The Complete WW2 Military Jeep Manual
- Military Maintenance for MB/GPW Jeeps 1941-45
- WWII Jeep Guidebook
Find More Information on the Web
There are many fine websites that have additional information on this topic, too many to list here and too many to keep up with as they come and go. Use this Google web search form to get an up to date report of what's out there.
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