Army Jeep History (1941-1954)
Article by Mark Trotta
As war in Europe escalated, the United States saw their odds of being pulled into a second World War increasing. Starting in 1939, the U.S. government began allocating money to build up all phases of their military. Reconnaissance vehicles, which were previously motorcycles and sidecars, were to be updated to light-duty trucks.
Requirements for the proposed vehicle, formalized in July of 1940, included a payload capacity of 600 pounds, wheelbase under 75 inches (later lengthened to 80 inches), a maximum 47 inches of tread, and four-wheel drive. The original gross vehicle weight of 1,300 pounds proved unrealistic and was raised to 2,160 pounds. A minimum of 85 lb-ft of torque, and a cooling system that would allow sustained low speeds without overheating, were the two main engine requirements.
The U.S. Army contacted 135 automobile manufacturers and asked each of them to submit working prototypes within 49 days. Three companies responded by the target date: American Bantam Car Company, Willys-Overland, and Ford Motor Company. Bantam, a small company based in Butler, Pennsylvania, was first to complete a running prototype. Testing began shortly after in September of 1940.
American Bantam Company
Seeing as their production cars were based on the British Austin Seven, Bantam's BRC (Bantam Reconnaissance Car) also used chassis components imported from the United Kingdom, along with other off-the-shelf parts. Four-wheel drivetrain components were made by the Spicer Company, who were also supplying the Ford and Willys Jeep prototypes.
Although the BRC tested well, the U.S. Army doubted the small company could produce the amount of units required. Bantam's design was presented to both Willys and Ford, who at the army's request, were encouraged to make their own changes and modifications. In light of their poor financial condition, Bantam could not protest this move. All three companies continued building prototype models.
Perched on solid front and rear axles and riding on an 80-inch-wheelbase, the Ford Pygmy was completed in November of 1940. The slotted steel grille incorporating the headlights was an original design and would be adopted by Willys in the final design stages. The Pygmy name was soon changed to GP.
Power for the GP came from a Ford tractor engine mated to a three-speed Model-A gearbox. The 120-cid engine was underpowered and unreliable, and most likely ruined Ford's chances of winning the lucrative Army contract.
The U.S. Army also tested prototypes built by the Checker Car Company. These four-wheel drive vehicles were developed in partnership with the American Bantam Company and featured four-wheel steering. After the military deemed them to be unsafe, the body design was sold to Willys-Overland, which mated them to their own small 4x4 truck chassis. This become the Jeep prototype that won the Army contract.
Ready for testing in November 1940 was the Willys Quad, whose designation soon changed to MA, for Military "A" model. Today, the 1941 Willys MA is perhaps the rarest of the early jeeps. Only 1,555 were built, and a just 27 are known to still exist.
Under the hood of the Willys Jeep was a four-cylinder flathead engine, heavily re-worked by former Studebaker engineer Barney Roos. Engine modifications included closer tolerances, tougher alloys, aluminum pistons, and a lighter flywheel. Using a bore and stroke ratio of 3.125" x 4.375", the L-Head engine produced 60-horsepower and 105 pound-feet of torque, which exceeded the Army's specifications.
Ongoing disputes and internal Army politics delayed the decision of who would be awarded the Jeep contract. Bantam, Willys, and Ford were each asked to make 1,500 vehicles for further testing. Many of these early WW2 Jeeps ended up being shipped to England, Russia, and other Allied Countries under the Lend Lease bill.
Engines were carefully tested to ensure they would run a minimum of 150 hours without failure. The Willys MA Jeep was capable of speeds up to 60-mph, and as could run as slowly as 3-mph. Turning could be done in short radiuses, and steep slopes climbed without tipping.
The combination of strongest motor and lowest bid helped Willys win the first production contract of 16,000 units. Now called the MB (Military "B" model), Willys Jeeps began rolling off the Toledo, Ohio assembly plant in mid 1941. The Willys MB was produced until September 21, 1945, with a total of 335,531 units built.
Read: American Automotive Industry During World War Two
The first 25,808 Willys MBs, produced from December 1941 to March 6, 1942, had a welded front grille and were known as slat-grille models. Other differences between these and later versions were the square fuel-tank tub, lack of glove box, and the addition of the word "Willys" stamped in the rear panel.
The Willys MB had a push-button start on the floor. There was no ignition key on 1941 models.
Ford GPW Jeep
Japan's attack on Pearl Harbor in December of 1941 brought the United States into the War. All U.S. military phases were quickly stepped up, and the Army now needed more Jeeps than Willys could produce. Because of their huge production capacity, Ford was granted a non-exclusive license to manufacture Jeeps to Willys' specifications. Ford's GP, now called GPW (General Passenger Willys), quickly went into production.
Ford built a total of 278,000 GPW's from January 6, 1942 to July 31, 1945. The early 1942 models had "Ford" in script on the rear panel.
Standardized features for the WW2 Army Jeep now included a three-speed floor gearshift (first-gear unsynchronized), a center hand-brake, and a 15-gallon gas tank located under the driver's seat. The six-volt electrical system included a 2H battery and 40-amp generator. Wipers were operated manually. At each corner of the truck, and at the center of either side, handles wre mounted for lifting the truck up and out of tough spots. Most (if not all) Army Jeeps were fitted with a pintle tow-hook.
Read: Jeeps In World-War-Two
World-War Two came to an end with the Allies' victory in the summer of 1945. The last Ford GPW was built in July 1945 and the last Willys MB was built in August 1945.
Post WW2 Jeep
Ford unsuccessfully sued Willys for the rights to the term "Jeep", leaving Willys full rights to the name. Although the Willys company neither coined the term nor designed the original vehicle, their name became synonymous with Jeep.
Willys continued to manufacture Military Jeeps, as well as Civilian Jeeps.
Jeep M38 (1949-1952)
Based on the civilian CJ3A model, the M38 military Jeep featured a waterproof 24-volt electrical system, as well as a sealed vent system for the engine, transmission, and transfer case.
The M38 was produced from 1949-1952, with over 45,000 examples produced. Approximately 2,300 M38 Jeeps were manufactured by Ford of Canada for Canadian Armed Forces. These were designated as the M38-CDN Jeep.
The majority of Jeeps used in the Korean War were remanufactured World War II jeeps.
Jeep M38A1 (1952-1971)
The second post-war military Jeep was the M38A1, which replaced the M38 in 1952. Also known as the Willys MD, these jeeps saw use during the Korean War, Vietnam War and others.
Kaiser Motors purchased Willys-Overland and changed the name to Willys Motors in 1953. A civilian version of the M-38A1, the Jeep CJ5, was introduced in 1954.
The M38A1 was powered by a 134ci inline-four engine producing 75 horsepower. This engine remained in production until 1971, after American Motors Corporation purchased Kaiser Jeep.
M38A1 production ran from 1952 to 1971.
Restore An Old Jeep