Deciphering the codes: Kaiser-Jeep and AM General 2 1/2-ton Truck Production

T he G-742-series cargo trucks–typified by the M35A2–have become an iconic symbol of U.S. military transport, having been the backbone of this service for half of the last century. Now, as these veterans are mustered out of service, it appears that they are destined to be the next “Jeep” of the enthusiast community. The vehicles are recognizable, nostalgic, plentiful, and affordable. Not since the M37 Dodges were released decades ago has such an opportunity presented itself to collectors. With the increasing number of restrictions on importation and sales of surplus military vehicles, it is likely that the M35A2 will be among the last tactical vehicles readily available to collectors and enthusiasts.

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Troopers wait as 2-1/2-ton cargo trucks are loaded somewhere in Korea, June 1970. The vehicles are a mixture of horizontally and vertically exhausted naturally aspirated Multifuel trucks. Nearest the camera, a Kaiser-Jeep truck built almost exactly a year before this photo was taken, beside it, another Kaiser-Jeep, this one built in February of 1968. How do we know? Read on! National Archives and Records Administration

Whereas production of the WWII Jeep, and even the various Dodge tactical trucks are well documented, the history of the M35A2 has remained shrouded in mystery. Mistakes on the part of government employees, as well as civilian contractors, have further fogged the history of these trucks.

This article will unravel some–but not all–of the mystery surrounding this vehicle. This information was derived from the examination of roughly 1000 vehicles. Additional information from readers and enthusiasts regarding these vehicles is welcomed.

THE BASICS

The G-742 series trucks were produced by a number of companies: Reo, Studebaker, Lansing Division of White, Curtiss-Wright, Utica-Bend, Studebaker-Packard, Kaiser-Jeep, General Products Division, and AM General. However, this article will deal only with those built by the latter three, as most trucks currently in or coming onto the collector market were built by one of these three makers.

The first step in this process is understanding what is meant by the terms serial number, VIN and registration number.

The Serial Number. The serial number is the number assigned by the vehicle manufacturer, and it is embossed in the frame, it is also known as the VIN, or Vehicle Identification Number. This number is of great interest to the truck builder and to a limited number of parts suppliers within the military, but of no interest to the military for record-keeping purposes.

The VIN.
The VIN number is stamped on the frame of the truck, near the steering box under the left front fender. It is a nine-digit number divided into a four-digit prefix and a five-digit suffix, for example, 0525-23669. Analysis of the production of these vehicles further breaks this number down. Please note that the terms used here are of the author’s own choosing and do not originate from official sources.

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The VIN should match the number on the dashboard-mounted data plate. This Kaiser-Jeep plate’s manufacturer number, 0225-21735, matches the frame number in the previous photo and includes the year manufactured, 1967.

The first two digits will be referred to as the lot number. The third and forth digits comprise the chassis designator while the final five comprise the sequence number.

The first two digits, or lot numbers, range from 1 through 10. However, a truck with an “07″ prefix has not yet come to light. These vehicles were probably produced by AM General for sales to a foreign government (any confirmation, or contradiction, of this is appreciated).

The next two numbers, or chassis designator, indicate the type of truck along these lines:

21- M44A2 cab and chassis
22- M46A2C
23- M342A2
24- M275A2 without winch
25- M35A2 without winch
27- M36A2 extra long wheel base cargo without winch
28- M49A2C
30- M185A3 without winch
32- M109A3
33- M292 style expansible van
34- M45A2 without winch
35- M756A2
36- M764
39- M35A2 with winch
40- M35A2C dropside
41- M35A2C with winch, dropside
44- M45A2 with winch
46- M36A2 with winch
47- M50A3 without winch

There are some exceptions to this list, however. The earliest M35A2C dropside cargo trucks were built on no. 25-designated chassis. The 40 designator did not appear until the fifth lot.

Notice that there are some numbers “missing” from the above list, specifically 26, 29, 31, 37, 38, 42, 43 and 45. Any reader with evidence of what type of trucks used these chassis is asked to contact the author.

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In later years, the data plate included an “identification number” which was an amalgamation of both the VIN number and the army registration number. In this example, “NK078Z” is the registration number, while “0640-11347″ is the true VIN of the vehicle.

The final five digit sequence number begins at approximately 10000. It begins anew at that number each time the lot number changes. However, evidence indicates that each five-digit suffix is unique within that lot. That is to say, there is not both a 0525-10011 and 0527-10011.Within lots, it appears the sequence numbers were just that–assigned chronologically in sequence.

With the above information, combined with known production dates of certain vehicles, determining the dates of other vehicles is possible. Whereas the production dates are handily embossed on the frame or even on the dash-mounted data plates in some trucks, this information is often missing or indecipherable. To determine the date of manufacture, the hobbyist must be a bit more resourceful. One place to turn to for assistance is the registration number.

The Registration Number. The registration number ,sometimes referred to as the “hood” or “USA” number, was assigned by the Army. It is roughly equivalent to the license plate number of your car.

When a contract (an order) for trucks is placed with a builder, the contract specifies the range of registration numbers to be applied to those vehicles. The contract does not require that they be applied in the same sequence as the manufacturer’s serial number, though in some cases they are. With almost no exception, the registration number of a vehicle, once assigned, does not change during the life of the vehicle.

The registration number, used in conjunction with the VIN, can be used as a guide to a vehicle’s history. Through the years, the Army has used various sequences of characters for the registration numbers. Some of these can be very useful when dating a Multifuel cargo truck.

1960 through 1968

In 1960, a new system was introduced, comprised of numbers and a letter, such as 4B 1234. The first number “4″ signified that the vehicle was a 2 1/2-ton truck. When the registration number reached 4B 9999, the next letter was used, as in 4C 0001, etc. Some letters were not used because they could be confused with numbers (such as I and O).

1968 through 1972

In 1968, the system was replaced with what, at least from the collector’s standpoint, was the ideal registration number system. T his system incorporated a “year” as the last two digits of the registration number. For example, the registration number 04A-46468 designates a 2-1/2 ton truck (“04″ prefix) built in 1968 (the final two digits).

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From 1968 into 1972, the vehicle’s year model was incorporated as the last two digits of the registration number. In this case, the number belongs to a naturally aspirated 1971 M35A2. U.S. Army TACOM LCMC History Office

1972 through 1982

For collectors, however, bliss was short-lived. By the end of 1972, the system changed once again when the “NK” numbering system was introduced. This is system is a little more vehicle specific than the previous systems, in that the alpha prefixes denote vehicle families rather than just weight class. While “NK” was used to designate Multifuel 2-1/2-ton cargo trucks, “NH” and “NJ” were used to designate diesel and gasoline powered vehicles respectively. The year of delivery was no longer incorporated into the registration number.

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Taken by AM General, this 1975 photo of a new M35A2C illustrates the registration number system employed from 1972 through 1982. Note when the army moved away from the overall semigloss olive drab paint scheme, the large white registration markings were abandoned as well. In their stead were smaller markings in black on the underside of the hood and inside the doors. U.S. Army TACOM LCMC History Office

1982 through 1987

By 1982 the Army changed the system again. The year returned, but now at the front of the registration number rather than at the rear. An example of this for a 1987 model is “87K2371.” The “newest” of these trucks thus far documented has been a 1987 model.

WHAT ABOUT THE CONTRACT NUMBER?

Starting in about 1968, the Army acquisition contract number appeared on vehicle data plates. Buried within this lengthy number is the contract year. For example, contract DAAE06-70-C-0001 was issued in 1970. However, vehicles often were still being delivered under a given contract number even many years later. Thus, the contract date should not be confused with the production date of a vehicle.

SO WHO BUILT MY TRUCK?

As stated in the introduction, this article concerns only three of the many makers of the M35-type trucks. A little history is perhaps useful in understanding the many nameplates found on these vehicles. Reo Motors of Lansing, Michigan, developed this family of vehicles in 1949 and began producing them shortly thereafter. Copies of the Reo-designed vehicles were ordered from South Bend, Indiana-based Studebaker Corporation in the early 1950s. This move was spurred in part by the national defense crisis of the Korean War, as well as desire, both from a strategic and political standpoint, to bolster the sagging sales of Studebaker.

In March 1963, the name of Willys Motors, Inc. was changed to Kaiser-Jeep Corporation. One year later, in March 1964, Kaiser-Jeep took over Studebaker’s military truck contract (which was for 5-ton trucks) and purchased Studebaker’s Chippewa Avenue plant in which to continue production. In February 1970, Kaiser-Jeep was purchased by American Motors Corporation. On March 26, 1970, Kaiser-Jeep became the Jeep Corporation. The South Bend facilities were part of the General Products Division. Just over a year later, on March 31, 1971, The General Products Division of the Jeep Corporation spun off and became AM General, a wholly owned subsidiary of American Motors. In 1983, cash-strapped American Motors sold AM General to LTV Corporation. Nine years later, a bankrupt LTV Corporation sold AM General to a group of private investors known as the Renco Group.

Lot Numbers.

The term “lot number” will be used to describe the first two digits of the VIN.

“01″ lot designator was used throughout 1966 and into the early part of 1967. These trucks were built by Kaiser-Jeep, as were lots 02 and 03.

“02″ lot designator appeared in 1967. Sequence number 18273 is the lowest 1967 VIN located (thus far). It was assigned registration number 4L-7291. Sequence number 23138 was built February 7, 1968, and assigned registration number 4M-2102. The highest sequence number located in lot 02 is 28762.

“03″ lot designator appeared in 1968, as denoted by the registration number (04A46468) of the earliest known “03″ truck (sequence number 10011). By sequence number 10703, the registration numbers had reached 04E11869. This truck was likely produced at the very end of 1968, as a handful of trucks with lower sequence numbers were assigned 1968 registration numbers. Remember, at this point in time, the registration numbers were applied to the trucks after they were built and inspected, not as they rolled off the assembly line.

The highest production number 1969 truck located to date carries serial number 25519. It was assigned registration number 04M-97669. The earliest 1970 truck located thus far is 26386, which was given registration number 04A36970. The newest “03″ lot truck identified is 30254, which was assigned registration number 04D59970. Lots 01, 02, and 03 all have Kaiser-Jeep data plates.

“04″ lot appears to comprise the smallest group of Kaiser-Jeep-built vehicles (except for the seemingly absent lot “07″ vehicles). Only 3,500 trucks span the sequence numbers. The registration numbers used are predominately 1969 series numbers. These trucks likely represented a new contract, rather than an addition to an already existent order.

“05″ trucks were contracted in 1970. This lot was one of the largest groups, comprised of some 16,000 trucks. Three manufacturers completed this lot. The first of these appeared with Kaiser-Jeep data plates, followed by the brief use of General Products Division plates, and finally AM General nameplates.

Registration number 04E56470 is the earliest known truck of the “07″ lot. It is a 1970 Kaiser-Jeep truck assigned sequence number 10020. By 1971, when sequence number 10290 was used, General Products Division was the name appearing on the data plates. That truck was given registration number 04C10871.

AM General was the badge applied to sequence number 10548, another 1971 product. The registration number of this vehicle was 04D66971. As production of the lot “05″ vehicles reached sequence number 25966 in 1972, registration numbers rose to NK01LC72.

Dropside cargo trucks apparently began to get their own chassis designator digits in 1972, as none have surfaced with the pre-1972 style registration number. Prior to 1972, the dropside cargo trucks used the same chassis designator as the conventional cargo trucks.

“06″ vehicles were contracted in 1973. All of the vehicles in this (and subsequent lots) were built by AM General. Details of year model breaks have thus far been elusive, but at least 2,000 vehicles were produced on the contract.
No lot “07″ vehicles have yet surfaced.

“08″ was a small lot, apparently of about 500 trucks. From sequence number 10000 through about 10500, these trucks were 1982 production. A few trucks exist with sequence numbers in this range and 1983 registration numbers – this is likely indicative that production of this lot began late in the year. Only a few trucks are sequentially numbered as 1983 production. The registration numbers for these trucks were assigned in the same sequence as the serial number. For example, when the serial number increases by two, so does the registration number.

“09″ vehicles apparently we re almost all produced in 1985, with only a handful of the 1000 or so vehicles of this lot leaving the assembly line in 1986.

“10,” the final lot, consisted of only a few more than 1,000 vehicles. These left the Chippewa Avenue plant in 1987. The registration numbers for these trucks began with “87″, and like the lot 8 and 9 vehicles, were assigned in the same sequence as the manufacturer’s serial number. On June 30, 1987, the Army asked the EPA for a “Conditional National Security Exemption” for the LDT engine, exempting it from 1988 and future standards.

POWERPLANT

From the inception of the G-742 (M35-type) trucks in 1949 through 1960, the vehicles were powered by the Reo-designed OA-331 six-cylinder gasoline engine. In 1961, this was replaced in most of these chassis types, including the cargo trucks, with the six-cylinder LDS-427-2 Multifuel engine. This turbo-supercharged engine was not equipped with a fuel density compensator, a hallmark of the later Multifuel powerplant. The exhaust routing was similar to that of the gasoline-powered trucks: Horizontal and exiting above the tandems on the right side of the vehicle.

Beginning in June 1965 the LDS-427-2 was replaced by the naturally aspirated LD-465-1C Multifuel engine, which had a horizontal, muffled exhaust. With the introduction of the LD-465-1C, the exhaust routing was changed from horizontal to vertical. For environmental reasons, the LD-465-1C was replaced with the turbo-supercharged LDT-465-1C. As the earlier engines wore out, they were to be replaced with the LDT. The LDT-465-1C in turn was replaced with the LDT-465-1D.

The previously mentioned exemption requested from the EPA was to allow the purchase of 15,000 2-1/2-ton truck engines over a five-year period. Instead of the desired five-year waiver, on September 30, 1987, the EPA granted a one-year exemption for only 3,000 engines. It directed the Army to “…establish a program to develop a cleaner configuration for the current engine.” This move sealed the fate of the longest-serving tactical vehicle design in the Army’s history.

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