Willys-Overland project.
Built around a Ford GPW, it was hurried into production before adequate testing was completed. The Seep’s much heavier weight put a strain on the 4-cylinder engine, hurting on-road acceleration and performance. In the water, a propeller was used to power the vehicle, but here too the little Seep was slow.
It also suffered from insufficient freeboard, a result of underestimating the GPW’s weight during the design phase, so it could easily be swamped in stormy waters. In the European theater, it wasn’t popular with GIs because they found it wasn’t very good for the rivers there, which often had steep banks that the Seep had difficulty overcoming.
Seep production was stopped after some 12,778 were produced. A lot of the vehicles were shipped to Russia, where they were better suited to the country’s low-lying rivers.
61 Not all Jeeps are created equal, at least in the eyes of today’s collectors. Among military vehicle buffs the early slat-grille Jeeps are worth more money that the later stamped-grille type, mainly because of their rarity. According to published sources, the stamped grille went into production in March 1942. Interestingly, there’s not a big price differential between the Willys MB and the Ford GPW. It probably comes down to the fact that Ford guys like Ford Jeeps and Willys guys like Willys Jeeps.
62 In many wartime photos of Jeep vehicles, you notice a vertical metal bar attached to the front bumper and rising to a height of about 5 feet or so. Probably you have wondered what it’s for. It seems that right after the Normandy invasion German soldiers came up with a nasty trick: They strung metal wires across the roads so that anyone driving in an open Jeep would have their neck snapped. It wasn’t long before enterprising GIs began welding the thick bars to the front of their Jeeps in order to break the wires before they could kill any more soldiers.
63 In the postwar era, the next-generation 1950–1951 military M38 Jeep (aka the Willys MC) received improvements that included a 24-volt electrical system, a one-piece windshield, and a tailgate. The tailgate was easy to add, of course, because it had been developed for the civilian CJ-2A. After the M-38A1 (aka the Willys MD) appeared in 1952–1953, many of the MCs were sold as surplus because the army realized the new M-38A1 was superior.
64 Ever hear of an M-38E1? It was a prototype military Jeep developed by Willys-Overland that bridged the gap between the flat-fender M38 and round-fender M-38A1. Designed in 1951, it combined the body tub of an M38 with unique front fenders that were flat on top but rounded on the edges. To provide the increased power that the military was asking for, it was equipped with the tall F-head fourbanger. In order to make that engine fit, the hood is tall but has a rounded appearance much like the M-38A1.
Another military prototype was the 1953 Jeep Bobcat. Similar in size to the earlier MB-L, this model was likewise a two-seater but light-ened to make it easier to transport by air.
The M-38E1 came within a whisker of being produced for the army, but in the end the M-38A1 was created and became the new standard army Jeep. The M-38A1 offered everything the M-38E1 did as far as mechanical improvement, but provided much more interior room with less weight.
65 Driving a World War II–era army Jeep in the winter was cold. The soft top gave little protection from freezing weather. Although a fair number of Jeeps were given homemade enclosed bodies built by enterprising GIs, a serious effort to “winterize” the Jeep didn’t occur until after the war when US occupation forces contracted with vehicle builder Steyr in Austria to refurbish Jeeps and build enclosed cabs for them. The new cabs were extremely well built, and that wasn’t surprising because the Austrian company that had built them had previously produced military trucks and staff cars for the German army.
66 Mention military Jeeps and most people think of the Jeep MB of World War II. Realistically, the category also includes the M-series trucks based on the civilian Forward Control Jeeps. There were four basic models: the M-676 was a standard two-door pickup, the M-677 was a four-door crew cab pickup, the M-678 was a van/carryall, and the M-679 Ambulance was similar looking but without rear side windows. Production began in 1964. These vehicles, when you can find one today, are highly collectible.
67 Perhaps the rarest military Jeep of all is dubbed the CJ-4M, a military prototype based on the proposed civilian CJ-4 and related to the M-38E1. How many were built? Perhaps as few as one or two. Photos you may see on the internet show a dark-colored military prototype with a snorkel kit, which may be the civilian model with a new paint job, as well as a long-wheelbase ambulance-type vehicle. So far, only one CJ-4 has been found, and it’s the original CJ-4 serial number 01 civilian prototype. The vehicle still exists. None of the military versions have turned up so far.
Engine and Drivetrain
68 All of the initial Jeep prototypes were powered by 4-cylinder engines because using a 6-cylinder engine would have resulted in a vehicle that was much too heavy to meet the army’s strict weight requirements. Bantam fitted its vehicle with a 40-hp Continental engine that was popular in lift trucks; the Ford GP was fitted with a Ford tractor engine good for 40 hp. Willys used the same four-banger that was in its passenger cars. The Willys’ mill was a rugged, durable 134.2-ci engine that developed 60 hp at 4,000 rpm and 105 ft-lbs of torque at just 2,000 rpm, which meant it was ideal for lugging along in low range yet also capable of fairly high road speeds. The Willys engine’s compression ratio was 6.40:1, meaning the doughty little Jeep could easily run on low-quality gasoline without knock or pinging.
69 The Willys engine originated in the 1926 Whippet, a line of popular, low-priced cars built by Willys-Overland during the late 1920s and early 1930s. Developing just 30 hp at the time, the little flathead mill was fine by the standards of 1926, but sadly out of date by 1938, when it was still being used in the new Willys 48 small car.
By that point, output had been boosted to 48 hp, but the engine was noisy, rough-running, and had a well-earned reputation for being short lived. The engine tended to wear out its bearings, burn pistons, and throw rods. It had a lot of problems.
70 That bad reputation was holding down sales. Who wants to buy a car with a tired, weak engine? So during 1939, the company’s management ordered the engineering department to do something about it. Engineering vice president Barney Roos, assisted by an extremely capable young engineer named Floyd Kishline, decided to go through the engine and fix the problems one by one.
The two men found many; in the end they had to redesign the engine block to give it full-length water jackets for better, more even cooling; design a new cylinder head; engineer a new carburetor and intake and exhaust manifolds for better breathing; design better valves, water pump, bearings, pistons, air cleaner, timing gears; and much, much more. It involved a lot of work and a lot of testing, but in the end, Roos and Kishline created essentially a new engine without the extreme expense of all-new tooling.
Engine output rose from 48 hp to 60 hp, a solid 25-percent improvement, and the engine ran much smoother and quieter. At the same time, durability was vastly increased. Prior to the redesign, a stock Willys 4-cylinder engine run at full throttle usually burned out in about four hours; that’s how bad the engine was. By the time Roos was finished with it, the redesigned engine ran 100 hours or more at peak rpm with no damage.
The Roos-Kishline redesign effort made the Willys engine the most powerful and most durable four-banger in America. They called it the Willys Go-Devil. It went on to become a legend and remained in production for decades.
71 The MB’s transmission is a T-84 3-speed manual gearbox that was produced by Warner Gear. The transfer case is a 2-speed unit manufactured by Spicer Manufacturing Company, which later was renamed Dana Corporation. Some sources report that the Brown-Lippe company also supplied
