New Universal Jeep Designs,
1949-52

This look at the Jeep prototypes leading up to the CJ-3B, M38A1 and CJ-5 models, is an expansion on the information published here in 1997-98 in The Missing Link: Discovering the Lost CJ-4 by Jim Allen, and CJ-3B Development 1949-53 by Derek Redmond and Todd Paisley. Those pages uncovered information about some of the prototypes developed by Willys-Overland engineers and designers between 1949 and 1952, and proposed an explanation of why they were never put into production.

The more detailed (not to say confusing) list of prototypes here, incorporates additional information from recent research by Jim Allen, Bill Munro, Ron Szymanski and the Japanese periodical J4.

Hubert Cossard drawings

The drawings above are by Hubert Cossard. (Elsewhere on the web, see Hubert's drawings of the entire Jeep f@mily.)

The illustrations in the text below are by Motonobu Sato, and are courtesy of J4 magazine, an annual publication in Japanese. (Note: See a complete set of the drawings in one image file (85K GIF) in a new window for easier comparison.)

Footnote numbers in the text⁽¹⁾ refer to the List of References at the bottom of this page.

CJ-3A

The CJ-3A was the civilian Universal Jeep in production by Willys-Overland during this period. It evolved from the CJ-2A in 1949, retaining the L-head 4-cylinder engine, as did the M-38 military version built during 1950-52. A thousand CJ-3A's were also produced in modified form for the U.S. Navy as the underwater CJ-V35/U in 1950. ⁽⁴⁾

The 3A was manufactured until shortly after the debut of the 3B in 1953. Much of the motivation behind the new designs for a Jeep to replace the 3A, was the need for a Jeep powered by the slightly larger F-head engine. ⁽⁹⁾

CJ-3B

I have long assumed that the experimental CJ-3A modified in 1949 with an F-head engine, referred to in Willys-Overland Engineering Release 5607 ("Front End Redesign", 29 June 1949 - 3 August 1950), must have looked similar to this final high-hood CJ-3B design. So far no photographs or other direct evidence has surfaced that can be clearly identified as the results of that 5607 project. But Jim Allen now guesses that 5607 was actually the X-98 (see below).

Perhaps not until Engineering Release 7474 ("4 FB Jeep", November 30 1951 - January 3 1952) was the final version created as model CJ-4A, later changed to "CJ-3B." This Jeep as it was eventually introduced in 1952, was a much less radical redesign than some of the prototypes created during the intervening two years. Todd Paisley speculates that materials shortages related to the war in Korea are what led to the decision to market this simple revision of the 3A. ⁽⁶⁾

X98

X-98

The Jeep bearing the experimental vehicle number X-98 had flat fenders, but with a front clip not unlike the eventual CJ-5 grille. Jim Allen now believes X-98 was the first F-head-powered Jeep utility, built in 1949 or 1950 under Engineering Release 5607, although other researchers such as Todd Paisley are not convinced that such a significant redesign of the front end would have been done so early.

Jim wrote on the classicjeep e-mail listserv: "I have several pics of this rig taken at different times and in different markings. In a set of Army photos taken at the Detroit Arsenal (20K JPEG), dated 24 August 1950, this vehicle bears the number X98 on the bumper and is called the 'truck, 1/4 ton, 4x4 with F-head engine.'⁽¹⁰⁾ Fred Crismon told me that the picture on page 224 of his book ⁽²⁾ (40K JPEG) was dated 8 May, 1951." (Jim Allen, CJML ⁽⁵⁾, 12 Oct 1999)

This is where things start to get confusing, with the same prototype being tested or photographed more than once, with different model numbers or markings. One author, in J4, states that "The civilian version of CJ-4M existed as X-98 in 1950." ⁽¹⁾ It did have civilian features such as a tailgate, side-mounted spare, and "WILLYS" stamped on the hood. The photos indicate that X-98 was actually tested by the military, however. They also suggest it was probably the same vehicle as the CJ-4M (see below). On the other hand, the dates of the photos do not tie the X-98 to Engineering Release 5607.

CJ-4M

Jim Allen's comparison of the various photos and their captions has convinced him that X-98 was in fact the same vehicle that was later called the CJ-4M under Engineering Release 5707 "New Model Release 473CJ" (21 March 1950).

"A test done 5 April 1951, at Fort Knox, KY, included two WWII era MBs, two M-38 model MCs, a standard commercial CJ-3A and an F-head rig they referred to as the "F-head truck." Each vehicle was given a test number, the F-head truck's being "205". This number can be seen on the front bumper in the pic in Crismon's book as well as on the Detroit photo, so I believe X-98 is the vehicle used for those '51 tests at Fort Knox." (Jim Allen, CJML ⁽⁵⁾, 12 Oct 1999)

There is another set of photos (front and right side, 130K JPEG's) dated 1 August 1951 which shows what appears to be the same vehicle ("TEST OPERATION" on windshield front and same AFF-B2 and 205 markings on bumper) with a captions tag that identifies it as "Project 5707, Model CJ-4M (Test vehicle loaned to Fort Knox)." ⁽¹²⁾

This caption connects truck 205 to the later Engineering Release 5707 project, rather than 5607. But Jim says he thinks that when a military version of the later CJ-4 was being contemplated, the old X-98 "F-head truck" was brought in as a stand-in, and given the designation "CJ-4M" until the real thing was built. The real thing would have been known as CJ-4M by Willys, and perhaps called M38E1 by the Army.

CJ-4

Exactly which vehicles were produced under which Engineering Releases is not entirely clear, but there are clearly two groups of prototypes. The second group has distinctive front fenders which are skirted all around, and a unique front clip shape, as seen on the CJ-4 photographed by Jim Allen in 1997 (30K JPEG). Mechanically it is similar to the subsequent MD model (M-38A1), but with standard rather than reversed front spring shackles. ⁽⁷⁾

Todd Paisley notes about the paperwork for Engineering Release 5707: "What is curious is that in the model column was "CJ-4." It was "X"-ed out and the model number 474CJ entered next to it." This project was closed and the Engineering Release 5607 project started back up from January 12 1952 - April 6, 1953. ⁽⁶⁾

These projects all happened within a short time, and overlapped significantly, so it's likely that the CJ-4 was in development at about the same time as the X-98. Todd Paisley has pointed out that the CJ-4 is seen with 1950 license plates in the photo on page 77 of the Arch Brown book, where it carries the number X151 on its bumper. ⁽³⁾.

M38E1

M-38E1

The author of the J4 article comments, "I read the Discovering the Lost CJ-4 article with many photos showing that the CJ-4 really existed. Those photos led to the conclusion that CJ-4 is the civilian version of M38E1, the prototype of M38A1." ⁽¹⁾ However, in this case it may be more likely that the CJ-4 came first, and as Jim Allen suggests above, a military version was then contemplated. The heavily retouched photograph of the M-38E1 may have been created at this stage, and the earlier X-98 prototype tested as a CJ-4M, until an actual CJ-4M (for "military") was built and given the M38E1 designation by the Army.

Engineering Release 6555, "Military Jeep with 4FB Engine" (28 December 1950 - 21 June 1951) appears to be the project leading to the M38E1, and it produced a vehicle similar to the CJ-4 but with snorkel and blackout light, shown in factory photos (left side and right side, 30K JPEG's) dated 5 March 1951. ⁽¹²⁾ The designation "M-38E1" does not appear in any known Willys-Overland documents, but does appear in Crismon's book. If it came from the Army, it would suggest that there was an actual vehicle.

Willys Engineering Release 6396 (Model CJ-4MA Ambulance) and Engineering Release 6825 (CJ-4MP Front Line Personnel Carrier) in late 1950 - early 1951, were apparently related projects, using a longer wheelbase and the same front end design as the M38E1. ⁽⁶⁾ CJ-4MA-01 appears in factory photos dated 23 March 1951, captioned variously as Ambulance and Personnel Carrier (60K JPEG's). ⁽¹²⁾

A photo of an ambulance with flat front fenders (30K JPEG) appeared in Kaiser Corporation's 1953 Annual Report, illustrating a mention of the continuing development of military Jeeps. There is also an undated factory photo of an ambulance M-38 (50K JPEG). Perhaps this vehicle is an early result of the 6396 project, which initially used the model designation "MC-A" which could be an ambulance version of the MC, or M-38.

M38A1

M-38A1

Engineering Release 6600, "Advanced Military Jeep, Model MD" (January 22 1951 - March 28 1952) became known in production as the M-38A1 military Jeep. Bigger, heavier and stronger than earlier Jeeps, it also was the first appearance of the rounded front fenders. Over 100,000 were built from 1952-1957, and some lasted into the 1970's in U.S. military service.⁽⁹⁾

The earlier Engineering Release 6400 "Jeep-Advanced, 1/4-ton 4x4, AJ" (6 October 1950 - March 15 1951) did not result in any known prototype. Bill Munro suggests it was an attempt to begin development of an all-new vehicle, and was scrapped when only Ford was invited to tender for what eventually became the M151 MUTT.⁽¹¹⁾

CJ-5

The CJ-5, the civilian Jeep derived from the MD design, did not enter production until 1954, allowing two years of glory for the CJ-3B. The J4 author speculates, "Willys wanted to sell the CJ-5 as M38A1's civilian version, but in 1953 all production lines were occupied by the M38A1, no space for the CJ-5. But on the CJ-3A production line, it was possible to produce a new Jeep converted from the 3A -- the CJ-3B." ⁽¹⁾ This explanation is not completely convincing, since Willys had in the past produced multiple models concurrently on one production line, and would continue to do so (see On the Line in Toledo).

Recent research by Bill Munro suggests that the reason Willys took so long to release the CJ-5, is that the Army owned the design and wouldn't give Willys permission to use it (perhaps partly because of pressure from Ford, who were building M-38A1's for the Army, in Canada.) This is at last a plausible explanation for the mysterious delay. Munro states, "Willys did not have enough money to build a completely new body for a new Hurricane-powered CJ. A compromise had to be found, and that was the CJ-3B." ⁽¹¹⁾

Further information on the prototypes is always welcome. Clearly some things have yet to be uncovered, including the mechanical specs of some of the prototypes. Other missing details include the results of Engineering Release 6400 (the "AJ"), documentation of the designation "M-38E1," and proof that X-98 was indeed the first F-head Jeep under Engineering Release 5607. -- Derek Redmond

References

J4, annual issue no. 5 (in Japanese), available from Morihisa Ochi (mutt@sage.ocn.ne.jp) for $US35 including airmail postage.
U.S. Military Wheeled Vehicles, Fred W. Crismon, Motorbooks International.
Jeep: The Unstoppable Legend, Arch Brown, Publications International.
Illustrated Buyer's Guide: Jeep, Jim Allen, MBI Publishing.
Classic Jeep Mailing List e-mail listserv (now succeeded by the Classic Willys Mailing List.)
Willys-Overland Engineering Releases, in CJ-3B Development 1949-53.
Discovering the Lost CJ-4, Jim Allen.
The Military CJ-4M, Jim Allen.
Pictorial History of the Universal Jeep, Jim Allen & Derek Redmond.
"Endurance: The CJ-3B Story," Jp magazine, April 2000, Jim Allen.
Jeep: From Bantam to Wrangler, Bill Munro, Crowood Press.
"Weirdfenders," Jp magazine, November 2001, Verne Simons.

Thanks to all the authors referenced above. Also Bill Norris for the photo from the 1953 Annual Report. -- Derek Redmond

See some original Willys Engineering Dept. Calculations: CJ-3B and CJ-4.

Also on The CJ3B Page, see The Universal Jeep, 1942-1986: A Timeline and Willys Production Figures 1945-61.

Last updated 8 January 2011 by Derek Redmond redmond@queensu.ca
http://www.film.queensu.ca/CJ3B/CJ4Prototypes.html
All content not credited and previously copyright, is copyright Derek Redmond

New Universal Jeep Designs,1949-52