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The Formation of Nihon Diesel Industries

UD Trucks' history dates back to 1935 with the formation of Nihon Diesel Industries. Nihon began as an enterprise that specialized in engines. Its founder, Kenzo Adachi, purchased diesel engine schematics from a Krupp-Junkers patent with aims to construct his own. Junkers, a German aircraft manufacturer founded in 1895, was able to develop a diesel aircraft engine through its subsidiary Junkers Motoren. The engine was later applied and modified by Krupp AG-a German steel company formed in 1810-in their own pursuance of the trucking industry. By 1938, Nihon applied its own alterations to create the ND1-a direct injection 2-stroke water-cooled diesel engine with a speed of 1500 rpm designed for commercial use. Adachi had larger aspirations than engines, though. In 1937 the company began production on its first truck by starting with the chassis. Any concerns about fitting the truck with a suitable engine were abated after the completion of the ND1 a year later.

In 1939, Nihon's first diesel truck was completed. Labeled the LD1, it was a 3.5-ton truck that was initially test-driven for 3,000 km without recording a single breakdown. This was a big feat for the truck and the company because the course of its drive consisted of several rough roads. The experience was a testament to not only to its durability but also its reliability. It traveled almost two times the length of the Japanese archipelago and suffered zero faults. That same year the ND2, a three-cylinder engine with 90 horsepower, was produced. With an added fuel injection pump, it became Nihon's first complete one-hundred-percent Japanese-built diesel truck.

Kanegafuchi Diesel and WWII

In 1942, Nihon Diesel renamed itself Kanegafuchi Diesel. Each of the engines were renamed the KD2 and KD3 in respect to the number of cylinders. Kanegafuchi used the engines during World War II to drill oil and man power generators. But the aftermath of the war was devastating to Japanese citizens and businesses alike. Resources were scarce, and businesses were having a hard time finding proper materials to construct anything, let alone find a way to put food on the table for their employees. Determined to find its footing, the company had an excess of steel but a lack of parts to construct a moving vehicle, so it resorted to creating and selling aluminum and steel pots and pans. Eventually the company restructured as the Minsei Sangyo Co., Ltd. in 1946 and set its sights on building a 6-ton truck called the TT9. Not long after, in the same year, the KD2 and KD3 resumed production. The TT9 was a hit for the scarce times, especially for its diesel engine which made it more economical.  They later went on to manufacture a diesel bus in the following year.

In 1950, after years of selling the TT9, they acquired the automobile division of Minsei Sangyo and relaunched as Minsei Diesel Industries, Ltd. in 1950. This lead to later production models such as the TN95. They mainly manufactured transportation vehicles, but it was under the Minsei name where something great happened: the construction of the UD engine that changed the industry and the face of the company.


The UD Engine and Nissan Diesel

The UD engine, which stands for "Uniflow Diesel," was introduced in 1953. It came as a two-cylinder, but was particularly lauded for its "uniflow" design. One in which air cycled through the cylinder and exited "out the top." This not only improved the engine's efficiency, but it also reduced noise, lowered engine weight by nearly 40%, and increased its power. The UD engine was so impressive two newer models were constructed in 1955. By offering three and four-cylinder engines, drivers could order a fit suited to their needs. The three-cylinder also came with 110 horsepower and the four-cylinder came with 150 horsepower. They all followed the Nihon and Kanegafuchi  naming convention and were respectively called the UD2, UD3, and UD4. This engine was also largely responsible for the name of the company that it's synonymous with today. Minsei trucks began to stamp the "UD" initials on the front of their trucks to display that they were running UD engines.

As for Japan, the roads were still unstable in certain areas and the interstate system was undeveloped in certain parts of the country. There were scarce, if any, Japanese made heavy-duty trucks, and one of the country's largest projects, the Kurobe Dam, sought foreign help to alleviate transportation issues. Minsei decided to firmly establish a Japanese heavy-duty industry that could navigate the underdeveloped roads, so in 1957 five prototypes were made for their new 6TW series. It was a series of firsts for the company, which included the creation of a 10 and 11-ton model in 1958 and 1959. It featured a 230-horsepowered diesel UD6 engine and two propeller shafts to relieve transmission and tire wear.

In 1960, the Nissan Motor Co., Ltd. acquired Minsei Diesel. That same year they renamed Minsei to the Nissan Diesel Motor Co., and introduced the 8-ton TC80G-their first cab-over-engine (COE) truck.  The main facet of the TC80G was its elimination of engine vibration that pervaded earlier COE models.

Furthermore, the development of the UD engine set Nissan Diesel on the international stage in 1968 in an export deal with Chrysler. It was a time where Japanese cars had very little success breaking into the US market and many Japanese automotive items were perceived as inferior. By agreeing to export engines to the US-based company, Nissan Diesel opened the door to begin the alteration of the industry's perspective of Japanese products. The UD engine was to be used not only on automobiles but also for Chrysler's Marine & Industrial Division.

Along with the UD came the SD that was to be applied to 2-ton trucks and luxury cars. The SD was developed in 1964 and was a four-stroke engine that came as a 60-horsepowered four-cylinder or 95-horsepowered six-cylinder. It was used for several applications in the marine and industrial fields as well. But apart from Chrysler, the SD engine also found a home with the Datsun and Nissan trucks for its impressive efficiency.

By the ‘70s Nissan Diesel's engines were in the US, but their trucks remained in Japan. This changed in 1973 when their first trucks were exported to Australia. Two years later the Condor series was introduced. With an ever-evolving transportation industry, many companies required mid-size refrigerated trucks that could carry "mixed-produce" and frozen goods. The Condor diversified Nissan Diesel, and two years later it became the first Japanese truck introduced with direct injection and a turbo.  It also featured a widened windshield and squared passenger and driver side windows for greater visibility.  

Nissan Diesel in the US

Nissan Diesel continued to expand its presence throughout the world and finally hit North American shores in 1984 with the arrival of the Nissan Diesel Motor Company. The plan was to sell Class 3 through Class 7 trucks. The first trucks arrived in 1985 as the Class 7 CPB12 and CPC12 models. Three years later, in 1988, Nissan Diesel teamed up with the Marubeni Corporation. Their investment helped solidify Nissan in the heavy-duty market and expanded Nissan Diesel into other industries such as lumber and construction. Years of research prepared them for the strict US emissions standards. In addition to passing the regulations, Nissan also aimed to improve fuel efficiency and performance, so they released the Big Thumb in 1990. It came with an aerodynamic styling and extended cabin. For a short period of time it was a viable choice for drivers seeking luxury and safety.

The Big Thumb served as the basis for UD's current flagship truck, the Quon. Released for the2008 model year, it was able to pass strict emission guidelines with a GE13 engine that could kick 520 horsepower. Increased comfort, visibility, and aerodynamics also improved the truck's fuel efficiency and performance. Safety features were enhanced with the first knee airbag, and comfort features were enhanced with a fold-up seat that created more cabin space for when the truck was idled. By this point, Nissan was rated the "Highest in Customer Satisfaction among Owners of Cab-over Medium Duty Trucks" by J.D. Power and Associates.

UD Trucks Today

In 2007 AB Volvo purchased the Nissan Diesel Motor Company for $1.1 Billion to gain a presence in the Japanese market. As a subsidiary of Volvo, Nissan Diesel changed its name to UD Trucks three years later in 2010. The UD icon was displayed on the trucks since Volvo's acquisition, so it was only right that the company renamed itself; and what better way than to represent the engine that started it all for the company. Today, the initials stand for "Ultimate Dependability," but the connection to the past is clear.

Since 2012 UD Trucks has left the US market after a decline in interest in the cab-over engine design and the slightly more expensive price tag than its competitors. Despite this, the company continued to innovate and build. Their newest project, completed for the 2014 model year, is called the Quester, and it features day and sleeper cabs and is designed to travel farther than your average 5-ton truck. With improved fuel economy, the latest and first all-built UD truck shows that UD has no expectations of slowing down.


UD Trucks is a registered trademark of UD Trucks Corporation. 1A Auto is not affiliated with or sponsored by UD Trucks or UD Trucks Corporation. See all trademarks.

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