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War Rigs - Jeep Autopsy: U.S. Military

Posted in Project Vehicles on January 1, 2007 Comment (0)
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Photographers: Courtesy of the DaimlerChrysler corporate historical collection
The Quad.

Everyone likes to say, "No good comes from war." Yeah, the Jeep is a real Debbie Downer. It has been famously called "the most useful motor vehicle we've ever had" by General Courtney Hodges, and it scored a memorable war motto of "The sun never sets on the Willys-built Jeep." The dogfaces considered it their best weapon in the field. Civilians were so gung-ho about getting their hands on one, its spirit is still alive and well in the JK. And to think, we could've come this close to buying Ford Wranglers.

The year was 1940, and the U.S. Army had a plea: Someone please build us a lightweight, rugged reconnaissance vehicle that could replace the fleet of motorcycles and Ford Model Ts. The invite went out to 135 manufacturers, and the spec requirements included a wheelbase shorter than 75 inches, it could be no taller than 36 inches, it required a two-speed transfer case, and the windshield should fold down. Its gross vehicle weight could be no more than 1,300 pounds.

'41 Willys MA

The whole "ask not what your country can do for you but what you can do for your country" thing hadn't yet been invented, so only two companies initially responded with bids: Willys-Overland and American Bantam. Willys-Overland blew the deadline, so Bantam got to build 70 pre-Jeep, Jeep-looking vehicles. A deadline extension was granted to Willys-Overland, and then Ford also signed up to play. That's when the prototype war began, and so did Jeep's military history.

Eventually, Jeeps were replaced by vehicles the powers that be believed were more refined, such as in the comfort department. Therefore, the M38A1 made room for the Ford M-151-the MUTT. The CJ-10 pickup was the last of the Jeeps for the U.S. military market. However, many Jeep models are still alive and well outside of North America, as Jeep licenses companies to build military rigs overseas. The J8 in this month's Dispatch is a military vehicle that Jeep itself built-but also for overseas.

A '55 M38A1.

Willys-Overland created the Quad, Bantam the Model 40 BRC, and Ford the GP Pygmy. They each excelled-and sucked-in different ways. Despite that, the army went ahead and ordered 1,500 from all three companies, and after further testing, took a little from column A, B, and C and Frankensteined an idea to be built on the Willys chassis. But don't pity Bantam and Ford-their models went to Russia and Great Britain (the latter called its Ford the Blitz Buggy).

The biggest problem with the Quad was its weight, and the biggest hit was its Go-Devil engine. But once it was army-fied, it shed about 360 pounds and was christened the '41 MA, with about 1,800 of them being built. It had a gearshift on the steering column and a hand brake on the left side. But it didn't take long for the MA to go through its first redesign; that same year it became the MB, which had awelded steel slat grille (Pygmy design), although the stamped grille came shortly after. The hand brake was moved to the center, and the gas tank was also moved underneath the driver seat.

An MC-A ambulance from 1955.

Because vehicle demand was so high and Willys lacked production capability, Ford won a contract to make the MB, too. Ford's version was the same vehicle Willys-Overland was building (with some minor differences), but it got the name GPW. Nearly 278,000 of them were built by Ford, making the MB a seriously mass-produced military vehicle. It clocked in at a total of 368,714.

The next key vehicle came after World War II: the '50 Willys Model MC, better known as the M38. It was the military version of the CJ-3A, but with a heartier frame and suspension and 24-volt electricals. It lasted through 1951, and 60,345 were produced. Also in 1951 (through 1971) was the Model MD, or M38A1, and 90,529 of those were made. It sported the future-CJ-5's round fenders, and its different front end was caused by wedging in an F-head mill. In 1960, the M38A1D debuted, which had a missile launcher-and the ability to fire tactical nukes! The cargo M-715 Gladiator descendent was produced from 1967 to 1969.

Here's the prototype CJ-4M, project 5707, from 1951, which was a test vehicle loaned to Fort Knox. its top was removed.

There are far too many other variations of the M-classes to detail here-everything from gun carriers and ambulances to hybrid 3/4-ton 6x6x6s-but they included the M-170, an ambulance version of the CJ-6, from 1953 until around 1967. The M-606 represented the military CJ-3B, while the M-606A2 and A3 were CJ-5 versions. Platform-style military rigs were the XM443-E1, called the "big brother" of the M-274 Mechanical Mule, which could carry six or convert for cargo.

For the mechanical sections of the military vehicles, we'll focus on the MA, MB, M38, M38A1, and M-715.

The MA used the Go-Devil, as did the MB and M38. The M38A1 sported a 72hp,F-head, 134ci Hurricane that made 114 lb-ft of torque, while the M-715 ran a 132hp, one-barrel, Tornado, 230ci six-cylinder with 7.5:1 compression and 198 lb-ft of torque.

An M274 mule.

All manuals: The MA and MB had a three-speed Warner T-84J, and the M38 and M38A1 had a three-speed T-90, while theM-715 had a four-speed Warner T-98.

The MA and MB featured full-floaters front and rear: a Model 25 and Model 23-2, respectively; both had 4.88:1 axle ratios. The M38 and M38A1 had a full-floating Model 25 front axle and a semifloating Spicer 44 rearend with 5.38s, while the brawny M-715 scored the full-float Dana 60 front and Dana 70 rear with 5.87s. Everyone got leaf springs.

The Model MX Bobcat prototype, project 9532, September 9, 1953.

Everything but the M-715 used a Spicer Model 18 with 2.43 Low range, although all the early military flatties had a 1.97 Low. The M-715 had a divorced NP200 with 1.96 Low.

One of the easiest ways to tell the difference between an MB and a GPW is to look at the front crossmember. Tubular equals Willys.

A '44 MB.

The official name of the Mule was Carrier, Light Weapons Infantry, 1/4-ton, 4x4 M274. It needed two birth certificates to fit all that.

SPEED READING
'41 WILLYS MB ENGINE
Wheelbase: {{{80}}} in. Go-Devil L-head
Overall length: 131 in. Displacement: 134.2 ci
Overall width: {{{62}}} in. Bore x stroke: 3.125x4.375 in.
Overall height: 69.75 in. Overall height: 69.75 in.
Curb weight: 2,315 lbs. Horsepower: 140 at 4,000 rpm
Transmission:
Warner T-84
Torque:
105 lb-ft at 2,000 rpm
Transfer case:
Spicer 18
Induction:
1-bbl Carter

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