Historic Truck Brands


The Kenworth story began in 1912, in Seattle, Washington, where brothers George T and Louis Gerlinger Jr operated a car and truck dealership known as Gerlinger Motor Car Works. 


In 1914 they built their own-design truck with a more powerful six-cylinder engine than the typical fours that were available. It also had a cab with steel, not wood, framing. The ‘Gersix’ – an abbreviation of the brothers’ surname plus ‘six’ – was introduced in 1915 and proved ideal for logging in the rugged Northwest.

In 1916 the company moved to Tacoma, Washington and attracted the attention of businessman Edgar K Worthington. In 1917, Worthington and his business partner, Captain Frederick Kent, bought the business.

In 1923 Worthington and Kent’s son reincorporated the business in Seattle as the Kenworth Motor Truck Company, a contraction of their surnames, as befitted the heirs of the ‘Gersix’. In the following year they sold 80 trucks.

From the outset Kenworths were custom-built, incorporating individual customer’s requirements where possible. Five models were listed by 1925, with capacities of 1-5-tons, powered by Buda four-cylinder petrol engines.

In 1926 Kenworth started making buses and in 1927 it produced three vehicles per week, opening an assembly facility in Canada, to get around import duties.

The top-spec’ models were powered by a new, 78hp six-cylinder petrol engine, driving through a seven-speed transmission.

In 1929 Kenworth opened a new facility in Seattle, unfortunately on the eve of the Great Depression that put the brakes on Kenworth’s growth of the late 1920s. Production was down and defaults on loans were common.

Kenworth diversified into state government business, making fire trucks from 1932. The company’s ability to custom-build to suit every fire department’s specific needs brought the company business that most of its competitors couldn’t get.

In 1933 Kenworth became the first American company to make diesel engines standard in its trucks and also introduced a sleeper cab option.

The Motor Carrier Act of 1935 introduced stringent weight and size restrictions on trucks and trailers. Kenworth engineers responded with aluminium hubs, cabs and lightweight four-spring and torsion-bar rear suspensions. Hydraulic brakes were introduced, along with a six-wheel option.

In 1936, the ‘bubble-nose’ Kenworth cab-over-engine (COE) model was unveiled. It wasn’t pretty, but  its short bumper-to-back-of-cab (BBC) dimension let it have longer bodywork or  trailer, inside the restricted overall length regulations.

Although custom-building was Kenworth’s attraction there was range of ‘standard’ trucks, with capacities of 2-10 tons, using Buda, Hercules or Herschell-Spillman petrol engines, or Cummins diesels.

By 1940 production had increased and around 230 Kenworth trucks left the factory.

One month after the Pearl Harbour attack on the USA, Kenworth joined the war effort and began production of  6×6, four-ton, heavy-duty M-1 Wreckers. These vehicles were equipped with cranes, fore and aft winches and cutting and welding equipment.  Kenworth implemented a production line for them and around 2000 were made by War’s end.

In addition to truck production, Kenworth manufactured components for Boeing B-17 and B-29 US bombers. Fearing air raids, the aircraft plant was disguised to look innocuous and the M-1 assembly moved inland.

Following the untimely death of its principal director, Kenworth became a wholly owned subsidiary of Pacific Car and Foundry in 1945.

In 1950, a Boeing gas turbine engine was fitted to a Kenworth and the first COE full-width ‘Bullnose’ cab was launched.

By 1951, Kenworth’s distribution had grown and exports made up around 40 percent of  sales . A major deal for Model 853s for the Arabian American Oil Co (Aramco) saw 1700 ordered. The Kenworth brand became an established oilfield player.

In 1956 the new Model 900 was introduced, featuring a dropped front frame section to make room for larger radiators. In the following year came a COE tilt-cab.

The 1958 Model 953 oilfield truck built on the success fo the 853, using Cummins Diesel power.

In 1961, two trend-setting new models were introduced by Kenworth: the W900 conventional (W for Worthington) and the K100 (K for Kent) COE.

The latter truck was aimed at maximum trailer length in East Coast States that restricted overall length. Kenworth now had appeal east of the Mississippi and that led to a new plant in Kansas City, Missouri. That year saw Kenworth achieve more than 2000 sales.

By 1966, there were 46 dealers selling Kenworth trucks throughout the USA and, with exports included, Kenworth sold nearly 4000 trucks during the year.

The dual targets of customisation and tariff reduction prompted Kenworth’s decision to open a plant in Australia, in 1968. Within two years it was producing right-hand drive conventionals and COEs for the Australian and other SEA RHD markets.

The 50th Anniversary of Kenworth in 1972 marked the first year in which the company hit the five-digit sales mark. To commemorate the event Kenworths featured gold-background hood ornaments – the Kenworth Bug –  replacing the polished aluminium ornament.

Chillicothe, Ohio was the location of Kenworth’s next expansion, bringing its production capability to 16,000 trucks in 1974.

The Oil Shocks of 1973 and 1979 made road transport companies around the world very sensitive to fuel economy, so, in 1985, Kenworth rolled out a streamlined conventional, called the T600A. The new design had a sloped nose and a set-back front axle with longer front springs. In addition to fuel economy gains the ‘Ant Eater’,as it was called in Australia, had better ride and manoeuvrability than a W Model.

The set-back-axle design was incorporated in the1986 T800, for North American markets. Kenworth unveiled the C500B severe-service truck in 1988, combining the durability of the C510 with the cab comfort of the T800. Also in 1988 came the T400A, for metro and regional work, followed by the T450 construction truck.

In 1990, Kenworth brought out its W900L, a 130-inch BBC, long-nose conventional with extended hood, aimed at the owner operator market.

In 1991 Kenworth released the T884, with front and rear steering axles and all-wheel drive, for the mining and construction industries.

In 1992 Kenworth announced the K300, Class 7 COE that featured a Brazilian-made VW LT cab and a conventional Class 7 contender, the T300, in 1994, using a modified T600 cab and as many existing chassis components as possible. Later model K300s used a newer cab, but that didn’t come to Australia.

A huge design and production shift for Kenworth came in 1996, when the all-new, wide-cab T2000 was unveiled to the public at the International Trucking Show.

The truck was shown in 112 and 120-inch BBC configurations with 75-inch Aerodyne sleepers. The T2000 incorporated all Kenworth’s aerodynamic experience and also reduced life-cycle costs and downtime for the owner.

Popular North American Kenworth models include the T600, T800, W900, and T2000. In 2007, Paccar introduced the T660, a more aerodynamic version of the T600.

In the early 2000s Kenworth released a modified T604 for the Mexican market, based on the Australian T604.


Kenworth Down Under

The first Kenworths arrived in Australia in 1962,  when several were imported by truck operator Ed Cameron and local assembly of Kenworths started in 1970. 

It took some time for the premium-priced Kenworth to be accepted, but the market-specific 1974 SAR proved to be a turning point. The ’S’ stood for short bonnet and the ‘AR’ for Australian Right Hand Drive. W900 models had great appeal to owner operators.

The COE K120 series and K140 twin steer trucks became prominent highway legends as ‘overnighters’ carrying time-sensitive freight between east coast capital cities.

The popular 1970s specification was Detroit Diesel 8V or Cummins 14-litre and V903 18-litre engine, and a 15-speed Fuller Roadranger transmission.

Today, Kenworth enjoys a dominant share of the Australian linehaul, road train and  heavy haulage market.

Australian models are assembled at Kenworth’s Bayswater facility in Victoria. Popular models have included the bonnetted T600, T604, T650, W925, T900, T904, T908, T950, T350,T400/ T401/404S/T404ST/404SAR and COE K124, K100E, K100G, K104G, K104B models, plus severe-service C500, C510 and C540.

Twin-steer and tri-drive variations have been produced over the years.

Kenworth Australia’s 2008 release was the ’08 Series’, including: the bonneted T358/A, T408SAR, T408, T608, T658, T908, C508 and C510. The new COE was the K108.

In 2011 release was the K200, T609, T409, T403,T409SAR, T359, T659, T909 and the C509 line-up.

Although the T2000 was trialled Down Under in the late-1990s its production wasn’t feasible in the Bayswater plant, so Australia had to wait until 2017 to get a wide-cab bonnetted truck.




Kenworth buses

When the company was still Gerlinger Motor Car Works, the first two full-chassis vehicles were school buses. In 1926, Kenworth developed a chassis specifically for school and transit bus operators, known as the BU and powered by a Buda six-cylinder petrol engine.

Kenworth expanded bus production through the 1930s, despite the Great Depression, releasing its most successful transit bus in 1933, based on the Model 86 truck.

Near the end of World War II, the company became part of the Pacific Car and Foundry Company. Postwar Kenworth buses were city and interurban buses and a trolley bus. 

Nearly 3000 buses were produced by Kenworth from 1949 to 1957, before the company decided to concentrate all its efforts on truck manufacturing.

National Parks Buses

Like the White Motor Company, Kenworth picked up some US National Parks business and this restored example once transported people from Seattle’s Olympic Hotel and Tacoma’s Winthrop Hotel to Mount Rainier from 1937 to 1962. 

Mount Ranier National Park is located, like Kenworth, in Washington State.

The multi-door, open-roof, 18-seat design is similar to that of the White National Parks buses that served in several US national parks from the early 1930s, but obviously, the proximity of the Kenworth factory was an influencing factor in the decision not to give the Mount Rainier National Park bus business to White.

The USA was the first country in the world to inaugurate national parks and the larger ones required some way of moving tourists between the park highlights. Bus tours around the parks were necessary, because, back then, most tourists arrived by train.

Since the 1920s White had produced open-top passenger buses for several US National Parks.

The Parks requested more protective buses and, in a four-way competition with Ford, REO and GMC, held by the National Park Service in 1935 at Yosemite National Park, the White Model 706 chassis emerged as the winner 

Starting in 1936, White produced 500 Model 706s, specifically designed to carry passengers through the seven major national parks in western USA. 

The distinctive vehicles, with roll-back canvas convertible tops, were the product of noted industrial designer Count Alexis de Sakhnoffsky and used bodies from the Bender Body Company of Cleveland. The Kenworth versions were very similar in layout and appearance.

This Kenworth bus is powered by a six-cylinder, Hercules JXD petrol engine, factory rated at 130hp (97kW).  The Hercules JX series powered many pre-World-War II American trucks and was one of the major power plants in US wartime military vehicles.

The original five-speed, constant-mesh manual transmission is a special-build gearbox that has an unusual shift pattern, because the three lower-speed ratios are crawl gears, to allow gradeability on the steep slopes of Mount Rainier. First is at the far left, opposite reverse and second is an ‘around-the-corner’ shift, with third gear opposite it. Fourth is another around-the-corner shift and fifth is opposite it.

Being a constant-mesh box – no synchromesh back then – with wide ratio gaps, meant that some of the national parks buses were nicknamed ‘Red Jammers’, because of the noise of less skilled drivers ’jamming’ the gear dogs into mesh.

Legacy Classic Trucks of Wyoming is best known for its remanufactured and repowered Dodge Power Wagons and Jeep Wranglers, but is also an accomplished restoration company that put thousands of dollars and many hours of labour into this KW rarity.

Literally every component was disassembled, restored and refitted, including the original wooden floor. However, the original leather upholstery was unserviceable and was replaced by Italian leather, made from 23 hides.

Period correctness extends to specially-made bias-ply tyres, fitted to the bus’s 20×6 Budd disc wheels.

In July 2020 the restored bus was offered for sale by Legacy Classic Trucks, for the princely sum of US$580,000.


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