Kenworth Truck Company
Type Division of PACCAR
Founded 1912
Headquarters Kirkland, Washington
United States
Industry Manufacturing
Products See listing

Kenworth Inc. is an American and Australian builder of heavy duty Class 8 trucks based in Kirkland, Washington, United States, a suburb in Seattle. It is a subsidiary of PACCAR which also owns Foden in the UK, and is also a former manufacturer of transit buses and school buses.


Kenworth began its history in Portland, Oregon. In 1912, the company was founded by brothers George T. and Louis Gerlinger, Jr. as a car and truck dealership known as Gerlinger Motor Car Works. In 1914, they decided to build their own truck with a more powerful inline six-cylinder engine. This was the first ever put into a commercial truck. The Gersix, as it was known, unveiled in 1915, was framed in structural steel, which along with its power, made the truck ideal for the rugged Northwest,[1] where it was used for logging.[2]

American truck - shell

The classic Kenworth

In 1916 the Gerlinger Motor Car Company moved to Tacoma, Washington. Seattle businessman Edgar K. Worthington was managing his mother's commercial building, where Gerlinger became a tenant, and became intrigued by the Gerlinger company. Worthington's tenant was doing quite well, or so it seemed, and the Gersix became a popular fixture in the Northwest.[3] However, the company, which then had offices in Seattle and Portland, was struggling and in 1917, Louis Gerlinger offered the manufacturing operation for sale. Worthington jumped at the opportunity. Together with his partner, Captain Frederick Kent, they formed the Gersix Manufacturing Company, to continue making a six-cylinder truck.

In 1919, Kent retired from the business and his son, Harry, became Worthington's new partner.[3] In 1922, Gersix made 53 trucks at its factory on Fairview Avenue at Valley Street. Under the new name, the company moved to 506 Mercer Street and later to 1263 Mercer Street. Trucks and motor coaches were assembled in individual bays rather than on a conventional assembly line.[4]

Kenworth was founded in 1923, taking the first three letters of "Kent" and the first five of "Worthington", capitalized with US$60,000. The following year, the company sold 80 trucks. In 1933[citation (source) needed] Kenworth became the first truck maker in the United States to switch entirely from gasoline to diesel internal combustion engines.

They were one of the first to come out with a cab-over-engine, or COE, model in 1957.

Current modelsEdit

Woolworths transport truck

A Modern Kenworth rig

Some popular North American Kenworth models include the T600, T800, W900, and T2000. Also, Paccar just recently introduced the T660, a more aerodynamic version of the T600.

In the early 2000s Kenworth (KW) introduced to Mexico the T604, based on the Australian T604 with a few modifications, mostly in the hood. It is optimized for pulling doubles in areas where a powerful engine is needed, however, the sales can't be compared to those of the T600 and T800.

In around 2004 kW introduced also to Mexico the KW45 and KW55, rebadged versions of the DAF LF45 and LF55, for distribution applications, a potential buyer has always been The Coca-Cola Company, as they have been replacing their old conventionals with new cabover trucks for shorter length with the same cargo space or same length with more cargo space.

During Mid-America Trucking Show (MATS) 2006 Kenworth announced the new T660. It's based on the T600, with superior aerodynamics and updated styling. It incorporates a completely new outer-body package including hood, bumper, headlamps, grill, and chassis fairings. The T660 will be the benchmark for high quality, on-highway trucks and maintains Kenworth's "Best in Class" approach.

The T800 has several versions, including the T800SH (Short hood, 113" bumper to back of cab (BBC)), T800W (Wide Hood, for a bigger radiator) and T800H (High Hood, for extra cooling area, but not as big as the T800W). They're mainly used in construction, off-road and special applications.


The brand claims to maintain an image of high quality, it has won five of six JD Power Awards in 2005, and was a clear sweep in the 2007 J.D. Power Awards for Heavy Duty Truck Product Satisfaction [1].

Australian OperationsEdit

Inside Kenworth conventional

Inside T408 SAR

Number OneEdit

In 1971, the first Australian-built Kenworth - a K125CR rigid for Ansett Air Express - rolled off the new production line at Bayswater, in Melbourne, Victoria's eastern suburbs. Since then, well over 40,000 trucks have been built at Bayswater. The majority are for the Australian market - arguably THE toughest climate to both sell and run trucks in - while some are exported to New Zealand and Papua New Guinea.


The following is a list of models released by Kenworth in Australia. The W and T range are the on-highway bonneted models, the K range are cabovers and the C range are aimed at heavy haulage, mining, and off-road high-mass road train applications.

  • 1970s: W900, K100C, K124, K125, and the W900SAR (the first fully designed and built Australian Kenworth, released in 1976)
  • 1980s: C500AR, T600, K100E, K144, T650 and C500T
  • 1990s: T900, K100G, T950, T604, T904, T350, T400, T401, T480 and C510
  • 2000s: T404, T404S, T404ST, T404SAR, K104, K104B, C540


Kenworth in Australia has always built cabovers, due in part to length restrictions in the 1970s that would not allow a long prime mover. They have become something of an institution, even more so after the introduction of B-doubles to Australian roads in 1987. Initially limited to a length of 23 metres (75 ft), time has seen them grow to 26 metres (85 ft) and weigh in at up to 68 tonnes (150,000 lb). Length restrictions also affected North America, with Kenworth dropping the cabover from their build program. This left Australia as the only manufacturer of Kenworth cabovers (note: NOT rebadged) in the world

Emissions RulesEdit

Tying in with the release of Euro-4 (Tier 2) compliant engines and ADR80/02 emissions standards, in 2008 Kenworth Australia released a new range of trucks. These were dubbed the '08 Series'. These included the following bonneted models: T358/A, T388, T408, T408SAR, T608, T658, T908, C508, C510, with the K108 the only cabover model. The T950 was dropped from the lineup owing to issues with fitting a large-enough cooling package within the bonnet/frame envelope.

Powerplant availabilityEdit

Since commencement of operations in Australia, Kenworth has had the availability of engines from all three maufacturers, namely Caterpillar, Detroit Diesel and Cummins.

In February, 2001, PACCAR (Kenworth and Peterbilt's parent) signed a long term engine supply agreement with Cummins. Although not an exclusive deal, PACCAR decided to drop Detroit Diesel from its engine list from July, 2001. This also came just after Detroit was bought by Daimler Chrysler, the parent of Freightliner and Western Star. [2]

In June, 2008, Caterpillar announced it was pulling out of supplying on-highway engines to all OEMs. This was ahead of the forthcoming ADR80/03 (Euro-5 or Tier 3) emissions standards. Caterpillar faced costly changes to engines that only generated a small amount of income. They have since gone on to release their own line of on-highway and vocational trucks.

More Emissions RulesEdit

In late 2010, Kenworth Australia released their updated model lineup, ahead of the 2011 change to ADR80/03 (Euro-5, Tier 3) standards. Released were T359, T403, T409, T409SAR, T609, T659, T909 and C509. An all-new cabover was also released - the K200. This represented the most dramatic redesign of the cabover platform in nearly 40 years. [3] The release of Cummins' ISXe5 Selective Catalytic Reduction (SCR) engines in early 2013 [4] added to Kenworth's engine arsenal, with both the SCR and EGR versions available for fitment.

Heavy tow truck

Kenworth T904

Bus industryEdit


BU seriesEdit

Bus production was a mainstay at Kenworth for much of the company's early years, and at one time was the company's most lucrative form of business. When the company was known as Gerlinger Motor Car Works, their first two full-chassis vehicles ironically were school buses based on the Gersix truck chassis. In 1926, Kenworth developed a chassis specifically for school and transit bus operators, known as the BU. The BU model sported a wheelbase of 212 inches that was expanded two more inches in 1927, and could be fitted with bodies ranging from 21 to 29 passengers. The BU model also heralded the return of the Buda six-cylinder engine, and remained the company's principal offering through 1931. The new model became so popular in the Pacific Northwest that production rose from 99 units in 1927 and 127 units in 1927, to 230 units by 1930. By that time, the predominant number of BU models produced were sent to school bus body builders, and were built for use in school districts throughout the Seattle and Puget Sound area of Washington State.

KHC seriesEdit

Kenworth continued expanding into bus production throughout the 1930s, despite the Great Depression being a major influence. To assist Kenworth's 80 factory workers - who were idled by the Depression, the company undertook a bold move by introducing a new line of buses in August 1932. Known as the KHC-22 (Kenworth - Heiser - City), the 23-passenger bus was developed by Kenworth engineers as a stock demo vehicle to help aid a glum sales picture, and to jumpstart the local economy. At a time of mild economic recovery, the KHC22 proved to be very popular and sparked a renewed interest in Kenworth buses. Major operators of the KHC-22 (later expanded to a 225-inch wheelbase, 33-passenger KHC-33, in September 1933) were the Portland Traction Company of Portland, Oregon, and Spokane United Railways.


In that year, Kenworth also released its most popular and successful line of transit bus, a conventional styled bus based on their Model 86 heavy duty truck. Powered by a Hercules JXCM engine, the model 870 as it was known, would soon be replaced by a model 871, which became Kenworth's standard line of buses throughout the early and mid 1930s. Experiments with "deck-and-a-half" buses would soon follow, as well as the company's very first experiments with rear-engine coach-type buses in 1936.

Production of Kenworth buses continued throughout the 1930s and into the early 1940s, and during this time Kenworth was manufacturing bus chassis for body builders such as Wentworth and Irwin (later renamed Wentwin), and Heiser. Heiser, long an often chosen body for school buses bearing Kenworth chassis, would later be purchased by Pacific Car and Foundry Company in 1937.

Kenworth changed its production line early in 1939, reflecting a desire to remain "in tune" with market forces. The conventional bus chassis, which had become poor sellers, were dropped altogether, and Kenworth focused its designs on more transit or "coach-type" buses with engines being located either underfloor or at the back of the bus.

By this time, Kenworth was a major force in transit bus production, and nearly every major transit company in the Pacific Northwest were running Kenworth buses. Seattle Municipal Railway purchased several new model 601s to replace the previous model H30s, which were powered by a Hall-Scott 135 engine underfloor and had bodies built by the Pacific Car and Foundry Company. Kenworth also built a model 612, which became the company's most widely distributed underfloor coach. 27 were built with 14 wheelbase variations (and seven engine variations), and all 27 were sold by as many as 15 different operators.


At the onset of World War II, Kenworth's bus production waned again, but Kenworth was able to remain afloat because orders were now larger than before. This was possible because the early effects of the war forced the amalgamation of several smaller, more regional operators into larger, territorial ones. These conditions meant more bus orders for Kenworth, only there were fewer buyers. Bremerton Transit purchased several buses in 1940 to accommodate the increase in ridership due to the preparations for the war itself.

In the face of these conditions, Kenworth still maintained production at about 40 units annually. In 1940, Seattle Municipal Railway purchased 30 buses in a single order, assisting Kenworth in breaking a production record. With low volume production, Kenworth was more than willing to build special order coaches. Gray Line affiliates Seattle, Portland, and Vancouver purchased several of these special coach orders known as Grayliner or Grayliner Junior buses, and the bodies for these buses were all built by PC&F. When wartime ensued, Kenworth found itself once again focusing its efforts towards war production, producing troop transports and a number of military variations of their commercial truck line.

Near the end of World War II, the company would become part of the Pacific Car and Foundry Company. In 1944, the passing of Kenworth president Philip Johnson meant that the major stockholders, the widows of Johnson, and Kenworth founders Kent and Worthington - could sell their controlling shares and stake of the company. Foreseeing a drastic downturn at war's end, Kenworth and PC&F believed bus production would play a pivotal role in jumpstarting the economy. It also saw an opportunity to hire former military truck and aircraft workers, and began a major push of four primary postwar models set to be relaunched in 1946.

The postwar Kenworth buses were part of a small group that included small intercity or interurban buses, dubbed the model K; a trolley coach known as the model E; a city transit bus known as the model N; and a model W - an intercity bus. Ironically, the choice of model designations derived from the first four letters of the name KENWorth. Later on, a one-door transit bus dubbed the Model O and a prototype school bus dubbed the model T,[5], which was the early forerunner of nearly 3000 model CT and LR buses produced by Kenworth from 1949 to 1957.

K & W seriesEdit

The Model K and Model W buses looked quite similar, but all similarities ended there. The differences were their length, side window design, and the choices of available engines. The model W had a pancake underfloor Hall-Scott 190 engine, while the K was powered by an International Red Diamond RD450 in the rear of the bus. The shorter model K was capable of hauling 25-33 passengers, while its bigger brethren could haul anywhere between 31 and 41 passengers depending on configuration. The Model N, as announced, would have seated 36 to 44 passengers in an underfloor engine configuration, but in 1947 it was downsized to a 32 to 36 passenger bus when the original design found no takers. After 1947, Kenworth began assigning numerals to the model designations to signify evolutionary variants in the design.

As production orders for the interurban model Ks and model Ws waned, Kenworth focused its attention on special orders including an order of 10 "Brucks"[6] for Great Northern Railroad in Montana, (an earlier version was built for Northern Pacific Transport, but was a split-level coach) and several Highway Post Office coaches. These "special order coaches" were based on the model T school bus, which entered production in early 1949, after additionally test-marketing a small 20-passenger bus known as the Carcoach (only one was built, but none entered full production).

T & C seriesEdit

Wahkiakum sd bus 6 03112007 12

A retired 1955 Kenworth T126 "Pacific School Coach", seen here in Cathlamet, Washington. Compare with image below, of same bus, taken after restoration has commenced.

The Model T school bus, which entered production after the last Bruck was built for Great Northern in April 1949, was an immediate hit with many school bus operators in the Pacific Northwest. The T-126 as it was known, boasted a unique four-pane windshield that offered unheralded forward visibility in any school bus at the time, and was the first school bus ever built to feature a roof escape hatch.[7] (now required equipment). Production of the T-126 averaged over 375 buses per year, making it Kenworth's most lucrative bus offering in the company's history up to that time. Shortly after its launch, Kenworth renamed the line the model CT. The model CT also came in several varying passenger capacities ranging from 55, 61, 67, 73, and 79 passengers. The model CT "Pacific School Coach" was powered by an International Red Diamond 450 inline six-cylinder gas engine placed at the rear of the bus, and a LeRoi H540 engine was made available for an LR-73 model that was produced in August of 1950. Some orders for modified model CTs were made available and sold internationally, with variants being sold to Uruguay and Venezuela, as well as the Middle East.

After the boon of school bus production, and to focus more on truck production due to a rising number of heavy duty truck orders, all bus production was shifted from Kenworth over to Pacific Car and Foundry in the middle of 1956. After some final cleanup, PC&F wound up completely outstanding orders for the Pacific School Coach in early 1957. Shortly afterwards, PC&F sold all rights, tooling, and equipment to Gillig Bros., a school bus manufacturer based in Hayward California. Gillig would later incorporate many designs of the model CT "Pacific School Coach" into their own Transit Coach line of school buses, starting with the 501- and C-series models in 1958 and 1959, respectively.

Bus industry legacyEdit

Wahkiakum SD Bus 6 2007

A retired 1955 Kenworth T-216 "Pacific School Coach" formerly from Cathlamet, Washington, is seen here in a photo taken after restoration has commenced. Compare with above image, of same bus, taken in February, 2007.

Kenworth's role in the transit and school bus industry has largely been forgotten. This is likely due to a number of factors including Kenworth's current status as a leading manufacturer of Class 8 heavy-duty semi trucks, and the fact that hardly any examples of Kenworth-built buses exist today (with exception of a few surviving model CT-73 "Pacific School Coach" buses and one remaining "Bruck").

In light of that fact, and having been a major builder of transit and school buses, interest in the history and preservation of the Pacific School Coach (as well as Kenworth's involvement in the transit and bus industry as a whole) has increased in recent years, especially in the Pacific Northwest where Kenworth's buses were most commonly found. The Gillig Transit Coach / Pacific SchoolCoach Online Museum, a website focusing on preserving Gillig's line of earlier-built school buses, was expanded shortly after its 2001 launch to include the history of the Kenworth-Pacific SchoolCoach. It has since expanded even further to include the entire history of Kenworth's involvement in the public transportation industry, as well as their local dominance in the school bus industry throughout the 1950s.

In 2006, at the American Truck Historical Society's 11th Annual Truck Show at the Mason County Fairgrounds in Shelton, WA, an historical society dedicated to preserving the Gillig Transit Coach and Kenworth-Pacific School Coach was officially dedicated.

Kenworth and the Seattle Fire DepartmentEdit

Because Kenworth manufactures their products in Seattle, Washington, they were able to furnish the Seattle Fire Department with nearly their entire rolling apparatus stock until the early 1980s.


Kenworth currently has manufacturing plants in:

  • Chillicothe, Ohio, United States
  • Renton, Washington, United States
  • Sainte-Thérèse, Quebec, Canada
  • Dandenong, Victoria, Australia - (Kenworth Australia)
  • Mexicali, Mexico - (KENMEX)

UK Model rangeEdit

The trucks are not officially sold in the UK, but are imported used by a few specialist dealers and were often used on Continental/Midddle east haulage operations. They also became 'popular' as show trucks when the custom scene started in the late 1970s and early 80s with truck shows copied from the USA. Trucks often feature radical custom paint jobs. Operators of Fairground rides and circuses also use american trucks as they are distinktive and they are exempt from length restrictions as the run road train style Drawbar set ups with a trailer and caravan or 2 trailers behind Ballast tractor units.

UK preservation Edit

Kenworth tractor unit at Lymswold - P7270153

A Kenworth rig at a UK vintage vehicle rally at Lymswold show 2008

A few examples appear at UK truck shows and Classic vehicle shows and similar events like Steam fairs with vehicle sections and a motive power for some of the exhibitors caravans and Low loaders.

In mediaEdit

  • A Kenworth W900 was one of the major vehicles used in the eighties cartoon series M.A.S.K.. It was also a part of the M.A.S.K. logo.
  • A Kenworth W900A tractor was used as the truck Jerry Reed's character "Cletus Snow" drove during the ilm] Smokey and the Bandit.
  • Jerry Reed's character "Duke Boykin" also drove a Kenworth K100 cabover tractor in the Canadian film High Ballin.
  • Motormaster, leader of the Transformers' Decepticon sub-group, the Stunticons, transformed into a Kenworth K100 Aerodyne. (Optimus Prime is often incorrectly identified as a Kenworth as well—the original toy was actually based on a Freightliner cabover)
  • A Kenworth K100 cabover tractor, with the 'Aerodyne' upper windows in the sleeper compartment, was used in the popular television (TV) series BJ and the Bear
  • A Kenworth W900 was used in the TV series Movin' On and was owned and driven by Sonny Pruitt (Claude Akins)
  • A Kenworth T2000 was used in The National Network's TV series 18 Wheels of Justice.
  • Three specially modified Kenworth W900Bs were used in the James Bond movie Licence to Kill
  • A Kenworth T600 was used in the main plot line in Dušan Rapoš's 1993 movie A Fountain For Susan 2, theatrically the most successful movie ever produced in Slovakia (as of 2007). A T600 is also depicted on the film's promotional posters and CD soundtrack cover, and appeared in History Channel's Ice Road Truckers driven by Hugh Rowland
  • Many Kenworth T-800s appeared in History Channel's Ice Road Truckers driven by Bear Swenson, Devon Neff, and Kevin McGinnis
  • Folk singer Richard Shindell wrote a song "The Kenworth of My Dreams" about restoring and driving a Kenworth truck

See alsoEdit



  1. Starner, D. Earl. A Pictorial History of the Straddle Carrier, 1988. 48p.
  2. Great Trucks
  3. 3.0 3.1 Kenworth History - at
  5. Pacific Photos - at Gillig Coaches
  6. KW Bruck - at Gillig Coaches
  7. Pacific Trivia - at Gillig Coaches

External linksEdit

Template:Paccar group

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