By Bob Westerman
The CJ-3A was produced for five model years, 1949 to 1953. Two other civilian
Jeep models overlapped the CJ-3A's production. During the 1949 model year the
CJ-2A was also available and in 1953 the CJ-3B became available. Unlike
modern vehicles, the change between CJ models was not distinct. The CJ-3A had
many features similar to the late CJ-2As. Likewise the late CJ-3A had some of
the new characteristics of the CJ-3B. Therefore all CJ-3As are not even the
same. The commonly accepted description of the CJ-3A seems to apply only to the
mid production vehicles. The lack of factory parts information from the CJ-3A
time period makes it very difficult to decide if and when changes were made.
Much information has been obtained from the CJ-2A and CJ-3A Parts List
(copyright 1949) and the 1945-1949 Master Parts List (copyright 1955). Many of
the listings in the 1945-1949 Parts Master List are for years later than 1949.
Both manuals contain some errors and omissions.
I am collecting information about the CJ-3As to help determine when changes
took place. Because anything could have happened to these vehicles in the 50+
years since they were manufactured, a large sampling of vehicles is necessary to
determine which assumptions are valid. From the information I have collected to
date the following differences are appearing. This information is preliminary
and it changes rapidly as new information is received from enthusiasts like you.
Vehicle Serial Numbers The CJ-2A/CJ-3A
Parts Book (copyright 1949) states that the beginning of production vehicle
serial number is 10001 with engine serial number 10001. Serial number tags are
attached with 4 screws to the engine side of the firewall near the air filter.
The vehicle serial number had a prefix of CJ-3A for the first 2 years of
production. During this time the serial numbers continued to climb with no
regard for model year. Starting in 1951, and continuing through final
production, a new format was used. The prefix was changed to indicate the model
and model year and the serial number itself was reset to 10001 at the beginning
of each model year.
Body Tags The earliest 1949 CJ-3As have a body number tag below the serial number tag on the firewall. Later in 1949, and for the remainder of production, the body tag was eliminated. Body tag numbers are initially close to the vehicle serial number and then skew to about 1200 less than the vehicle serial number. What does this mean? How could there be less bodies than vehicles? The body tag to the left is from a 1949 CJ-3A, thanks to Andy Testo for the photo. During late 1948 to early 1949 Willys began to build their own bodies. Prior to that American Central Manufacturing (ACM) manufactured the bodies. Were the body tags eliminated when the body building was brought in-house?
Starters and Generators Starter and generator numbers are found on a tag that is riveted to their housings. Three different starters were used. The first vehicles used the Autolite MZ-4137. In mid 1950 the starter was changed to MZ-4162, according to Autolite manuals. The 1945-49 (copyright 1955) Parts manual lists a change in the starter push rod at vehicle serial number 51911. This is likely to be the serial number where the starter change took place. Both of these starters are interchangeable, are activated by a foot pedal linkage, open nosed, and use a 124-tooth flywheel. The third starter is Autolite MCH-6203. This starter is a key start with a solenoid mounted to the top of the starter and is the closed nose type. It uses a 129-tooth flywheel. The 1965 Universal Service Manual states that this third starter was put into production with vehicle serial number 30973 and, on a different page, engine serial number 130859. By adding the prefixes 452-GB1 to the vehicle serial number and 3J to the engine number, the result is vehicle 452-GB1 30973 with engine 3J130859. These are credible numbers for a 1952 CJ-3A and this data fits perfectly into the information collected to date. The engine block change to the larger rear flange also occurred at this serial number.
The generator changed from the Autolite GDZ-4817 to Autolite GDZ-6001, most
likely during the 1950 model year. Then at vehicle serial number 453-GB1 17807
the generator and regulators were changed to provide a greater output. According
to Service Bulletin 53-5 this generator provided a nominal 45 amp output. This
last generator may have been an Autolite GGW-4801 or GGW-7404. Thanks to Bill
Norris for copies of the Bulletins.
and Driveshafts One of the common improvements associated with the CJ-3A is
the model 44 rear axle. The model 41 axle was actually used in the 3A until the
end of the 1950 model year. The 1945-49 parts book (copyright 1955) lists this
change at vehicle serial number 62488 (very late 1950 model year). On the
Classic Willys Message List Todd Paisley stated that Engineering Release #6427
Rear Axles (Spicer) - Change from Spicer Model 41 to Model 44 was started on
October 31, 1950 and and implemented on November 30, 1950. The rear axle can be
identified by the shape of the differential cover (see photos at left). The
model 41 axle uses a round differential cover while the model 44 cover has
A larger diameter rear driveshaft appeared at about the same time as the rear
axle change. Early CJ-3As used a 1-1/4" diameter rear driveshaft while the later
3As used a 1-3/4" diameter rear driveshaft. I have not been able to pinpoint
when the change was made because during the 1951 model year I am seeing both
small and large diameter driveshafts randomly. By 1952 all driveshafts are large
Radiator The first CJ-3As utilized a bottom-mounted radiator, like the
2As. The bottom of this radiator was bolted to the frame crossmember and had a
rod that extended between the bracket on the radiator top tank and the firewall.
The side mount radiator was bolted to the grill on both sides instead of the
frame, and lacked the top connecting rod. The change to a side mounted radiator,
according to the 1945-49 Master Parts list (copyright 1955), was after CJ-3A
21656. Keith Buckley also added that the Air Deflector portion of the grille
changed from 22 gage to 18 gage at this time. This logically was done to support
the extra weight of the radiator. Surveys of existing vehicles is showing the
possibility of a short run of bottom mounted radiators after the side mounted
radiator had been put into production.
Hood The early CJ-3As had short hood blocks and they were not
equidistant from the hood center seam. In late 1950 to early 1951 the hood
blocks changed to the taller type associated with the 3A and their location was
equal distance from the hood centerline. This change appears roughly before
serial number 451-GB1 17000.
Early horn button inside nut Late button with rubber cover Late style with cover missing
Tailgate A minor change was made to the tailgate in mid 1951. The M38, a sibling of the CJ-3A, required four cutouts in the top flange of the tailgate to allow for rear seat bracket and spare tire carrier attachment. This modified part carried over to the civilian Jeep although it was not necessary on the CJ. The photo below shows a late tailgate with 3 of the 4 cutouts visible. The 4th cutout is the longer oval type on the far left side of the tailgate. See the excellent article, Tailgate Reading, on the CJ-3B Page for more information about this change.
Colors The first CJ-3A windshield frames were painted the body color.
Most original vehicles after mid 1952 seem to have black windshield frames
instead of body color windshield frames. This is consistent with the CJ-3B,
which had black windshield frames. This change appears at about vehicle serial
number 452-GB1 20000.
It seems that most CJ-3As have been repainted since they left the factory. Original body color paint can often be found in areas where the re-painter missed. Look under the dash, behind bolted on components like the serial number plate, and low on the firewall where it is oily.
Jim Allen's book, the Illustrated Buyers
Guide, Jeep shows the following vehicle colors available for the CJ-3A
Sherwin-Williams and Dupont paint chip catalogs from 1949 to 1951 list
available Civilian Jeep colors as Emerald Green, Luzon Red, and Potomac Gray.
Horizon Blue is also listed only for the 1951 Farm Jeep. A 1951 Ditzler Bulletin
lists colors for Universal Jeep, Farm Jeep, and Jeep Tractor as Luzon Red,
Emerald Green, Potomac Gray, Horizon Blue and Universal Beige. For 1952 Dupont
shows Hampshire Green Metallic as the only Jeep (CJ) color. Ditzler has
Hampshire Green and Horizon Blue. In 1953 Dupont, Rogers Paint Products, and
Ditzler paint chips only have Woodstock Green listed. A Ditzler Bulletin dated
July 7, 1953 adds Cadet Gray and Saber Rouge.
With all this conflicting information it is hard to decide what colors were
actually used. The following data is compiled from owners of existing CJ-3As as
Original wheel colors are difficult to find. The wheels on many vehicles have
been replaced since wheels are easily exchanged. The
as seen on the CJ-3B Page has reddish orange wheels (Sunset Red?) so we can
assume that in 1951 there were several different wheel colors depending on the
body color. Did the last 3As use just black or white wheels like the later CJs?
The 1945-49 parts book (copyright 1955) lists available replacement seat
colors as Slate Gray, Olive Drab, Red Barcelona and Dark Gray.
Canvas top replacement parts were only available in Slate Gray according to this manual.
From the G503 CJ Technical Knowledge Base comes this information; Engineering Release #5248 Gas Tank Assey. (Painted Black) - Revise Paint Spec. From body Color to black Enamel started on 1/27/49 and issued 2/15/49. This indicates that the early 1949s had body colored fuel tanks. The change to black fuel tanks may have occurred at about the same time as the body serial number tag was eliminated.
More data is needed to confirm these findings. Much of this information does
not seem to be written down anywhere so your input is very important to document
the changes. If you own a CJ-3A, or have any information about the 3As, please
fill out the following survey and e-mail it to firstname.lastname@example.org. The answers
to any of the questions is helpful even if your Jeep has been modified or you
can not answer all the questions. Your input can help record the history of the
I would like to thank everyone who has helped by providing information. There
are far too many people to name. All the people who took the time to provide
data about their CJ-3A deserve credit as this couldn't be done without them.
Special thanks to Harold West for help with the data and ideas about how to
analyze the information.
More information and all comments are welcome
Willys CJ-3A Questions