The Willys MD, formally the M38A1 Truck, Utility: 1/4 ton, 4x4, or the G758 by its U.S. Army Standard Nomenclature supply catalog designation, was a four-wheel drive, military light utility vehicle, made by Willys and Willys Motors / Kaiser Jeep from 1952 to 1971. It was widely procured by the U.S. military from 1952 until 1957, after which U.S. purchases were reduced to the U.S. Marine Corps. The Marine version had minor differences from the units used by other branches.
The MD was the first Willys jeep with a significantly restyled body, immediately recognizable by its rounded hood and fenders. It formed the basis for the civilian and commercial Jeep CJ5, built for three decades (1954–1983), and subsequent models, and called the first 'round-fendered' Jeep. Although hard doors were still not available, the soft-top could be complemented with soft side panels and little hinged doors, that consisted of a thin steel frame with cloth and plastic window.
For the U.S. Army, the MD was replaced by the Ford M151 jeep, from 1960. Low volume production of M38A1s for export to friendly foreign governments continued through 1971. Production totalled 101,488 units (80,290 domestic / 21,198 foreign sales). M38A1 jeeps saw extensive service during the Korean War, Vietnam War and several other conflicts.
Description
The M38A1 / MD was the second post-war evolution of the World War II Willys MB jeep (after the M38 or MC; F engine Prototypes), and the first Willys Jeep to feature the new rounded fenders and hood body design that would become the distinguishing body style of the 1955 CJ5, and which was carried through for decades on the CJ6, CJ7 and CJ8 Jeeps. The M38A1's wheelbase grew by a single inch (2.5cm), and overall length by some .
Drive Train
The M38A1 was the first Army jeep to use the Willys Hurricane F-Head 134 inline-four engine. This engine was taller than the 'Go-Devil' engine that powered the WWII era jeeps and the M38, and was the reason for restyling the body over the higher power plant.
Otherwise, the MD had a T-90 3-speed transmission, Dana 18 transfer case, either the Dana 25 or the Dana 27 front axle, and Dana 44 rear axle.
Variants
M38A1 (MD)
Basic utility version. Would regularly be equipped with M2 .50 cal machine gun and/or radio equipment and antenna-mount. On early units (1952–1953) the front grille was mounted with two 45 degree hinges, one at each frame rail, to flip it forward for maintenance.
M38A1C
Modified version equipped with a M40A1 106mm recoilless rifle. They were fitted with a .50 caliber M8C semi-automatic spotting rifle. The spotting would be fired first, to ensure a first round hit with the 106mm recoilless rifle. The .50 caliber spotter cartridge was 22mm shorter than the standard .50 caliber machine gun cartridge. A slot was provided in the windshield frame for the 106mm barrel when traveling.
M38A1'D'
Several dozen M38A1s were converted, mounting a tactical nuclear Davy Crockett Weapon System, fired by a large diameter smoothbore recoilless rifle – either an M28 120mm, or an M29 155mm gun. The vehicle carried two M388 projectiles, mounting the Mk-54 nuclear warhead. The range of weapon was approximately 1.25 miles (2 km), with the M28 gun, or 2.5 miles (4 km) with the M29. This vehicle/weapon combination was also referred to as the "Battle Group Atomic Delivery System", and was allocated to airborne units.
M38A1 Welding Unit
Just one unit is assumed to have been built, originally fitted with a Harger & Valentine field arc-welding system, powered by a power take-off driven generator.
M170 ambulance
The M170 Frontline Ambulance variant of the M38A1, with a stretched wheelbase, formed the basis for the later civilian Willys CJ6 Jeep. The spare tire was relocated in a special wheel well on the right interior side of the vehicle, and a larger fuel tank was fitted. Capacity was six seated passengers, or three lying on litters. A total of 4,155 M170 ambulances were designed and built by Kaiser Jeep of Toledo, Ohio, from the mid-1950s to the early 1960s.