Like other heavy-duty vehicles, a truck’s popularity is usually measured by its reliability, capacity, and lifespan. However, the fame of Kenworth W900 goes beyond these three factors–with a rich history and appearance in blockbuster films, there’s no wonder the unit is one of the most note-worthy names in the trucking industry.

Dubbed the “perfect fusion of cutting-edge technologies, expert engineering, and classic styling,” the Kenworth W900 remains to be one of the crowning glory of Kenworth Truck Company. In this article, we’ll go through the history and development of Kenworth W900 units to understand why it remains one of the most preferred models among companies, contractors, and drivers alike.

History of the Kenworth W900

The Kenworth W900 is a kind of conventional-cab truck produced by the Kenworth Truck Company. The unit’s history and development of its current model are as interesting as its style.

The predecessors: the 1939 500-series and the 1956 900-series

The Kenworth 500 series, launched in 1939, is considered to be the basis of the company’s commercial truck line until the mid-1950s. Kenworth produced approximately 226 units of the 500-series until the 1940s before focusing on the production of 4-ton 6×5 M-1 recovery vehicles because of World War II.

Old Kenworth 500 Series

Old Kenworth 500 Series

Due to the pressure brought by the company’s government contracts, Kenworth continued to focus on manufacturing military transport vehicles until 1945–sidelining the development of the 500-series. After World War II, Kenworth redesigned its cab-over-engine (C.O.E.) product line, later known as the “Bull-nose” 500 series.

1956 Kenworth W900

1956 Kenworth W900

In 1956, Kenworth introduced the 900-series conventional-cab truck replacing the 500-series. The line graced an all-new “drop-frame” chassis with the cab-surrounding-engine (C.S.E.) cabover replaced by the K-series C.O.E. It also sported a standard side-opening “butterfly” hood with a forward tilting fiberglass. 

Introduction of the Kenworth W900

In 1961, Kenworth recognized the need to release a conventional-cab truck designed specifically for highway use. For this reason, the company introduced the W900-series, a Class 8 truck designed to replace the 900-series conventional. The new line sported the letter “W,” short of “Worthington,” one of the company’s founders. However, because of the line’s popularity, the letter “W” was soon popularized as a term for set-forward axle cab trucks.

The notable changes of the W900 from the 900-series included raised cab roof height, windows and two windshield panes mounted together, a slight widening of the radiator for a cooler engine, and fender-mounted headlights. The iconic tilting hood of the 900-series remained the standard setting.

The popularity brought by its predecessors was further elevated when Kenworth continued to release upgraded models of the W900 model for 60 years. 

Development of engines, bodies, and parts of the Kenworth W900 series

As mentioned earlier, the Kenworth Truck Company released several iterations of its popular W900 series. Here are some of the most popular ones that dominated the market during their time.


The first release of the W900-series ran for over 4 years (1961-1964). The conventional-cab truck introduced the “bulkhead style” doors with full-length hinges to the market, which didn’t just influence its successors but also its competitors. Another iconic feature of the first release was the wide-style vent windows with mounted door handles.

1961 Kenworth W900

1961 Kenworth W900

The W900 model family wasn’t just popular with utility companies, contractors, drivers, or truck enthusiasts–it also became a familiar sight to the masses. The W900 was featured in numerous films and television shows such as Smokey and the Bandit (1977), BJ and the Bear (1979), and James Bond: License to Kill (1989). But the model was formally engraved into pop culture when the cartoon series M.A.S.K (1985) didn’t just use the W900 in the series but also used the truck’s design on the cartoon’s official logo.

Because of its popularity, the W900 model remains to have one of the best resale values in the truck industry. 


In 1965, Kenworth decided to further upgrade its popular W900 with the available technologies of the time. The changes applied to the W900A were mainly on the exterior side to accommodate new engines and improve the comfort and convenience of the riders.

1965 W900A

1965 W900A

The truck’s hood was lengthened by several inches to increase its radiator size further and accommodate larger diesel engines. In 1972, the doors were changed with the model-adapting larger windows and narrower vent windows for better road sighting. Aside from this, the door handles were re-positioned to the bottom of the doors and transformed from a lever-style to a pull-style model for easier use. The Kenworth badging was also changed into a grille emblem with hood badging in 1973.

Most importantly, in 1976, Kenworth introduced the Aerodyne Sleeper Cab for the W900A–the first factory-produced sleeper cab with a raised roof. The Aerodyne had twin skylight windows which weren’t present on the regular W900A units. 

While it may be common these days, the W900A Aerodyne Sleeper Cab was a groundbreaking development within the trucking community at that time, as comfortable living accommodations for truckers were minimal, if not completely non-existent. The model would be significantly influential to W900L and other sleeper cab trucks. 

The W900A ran from 1965 to 1982, approximately 17 years before it was replaced by the W900B, except for Mexico (Kenmex), which continued producing W900 units with rectangular headlamps.


The W900B entered the market in 1982, replacing the circulating W900A model. Compared to the changes of W900A from the W900 series, the W900B had undergone more significant changes than its predecessor–sporting exterior and electrical upgrades. 

1982 W900B

1982 W900B

The distinguishing difference between W900A and W900B was the latter’s use of rectangular headlamps. Aside from this, the newer unit also has better hood line height and higher mounting on the frame to improve engine cooling. W900B also sported a better frame for the cab and sleeper units. 

Due to the rapid and vast development of electrical gadgets, the W900B was designed with new modular electrical components, significantly improving the efficiency and ease of use of the conventional-cab truck.

The current production of the Kenworth W900 truck is still largely based on the W900B model. However, the company introduced two model variants during the succeeding years–the W900S and the W900L.


Introduced in 1987, the Kenworth W900S was originally released in the market to comply with upgraded emissions standards. The model had an upgraded powertrain for better emission and other functional changes from the W900B model. In terms of the exterior design, the W900S adopted the sloped hood of the T800, which was released in 1986. 

1986 Kenworth W900S

1986 Kenworth W900S

While the engine, design, and overall functionality of the Kenworth W900S were nothing less than impressive, it was overshadowed by the W900L, which was considered one of the most popular vehicles sold by Kenworth.


Like the W900S, the W900L was introduced in 1990 mainly to comply with upgraded emissions standards. However, the changes done by Kenworth to accompany the said compliance were surprisingly loved by contractors and truck drivers.

1990 Kenworth W900L

1990 Kenworth W900L

The W900L was introduced as the longest version of the W900 line (“L” for “long”), with extended B.B.C. from 120 to 130 inches. It was initially produced as a limited edition to commemorate the W900 B’s appearance in the James Bond Movie License to Kill (1989), complete with gold-plated Kenworth badging and James Bond 007 emblems featured in most James Bond merchandise during the time. 

Soon enough, the W900L unit came into full commercial production due to the overwhelming demand. Because of its entertainment roots, the W900L sleeper models came with a whopping 86-inch studio unit, complete with new T.V. & VCR units, cassette and CD players, and 8 300-watt sound systems. 

No wonder the W900L became one of Kenworth’s most popular designs–as it had both functionality and fun.

Other Iterations of the Kenworth W900

Kenworth continues introducing various iterations of the W900 units, especially the popular W900L. In 1994, the Aerocab/Aerodyne 2 sleeper became an option for the W900B, W900L, and T600B. Aside from better and higher roof designs, the newer versions of the sleeper truck sported more spacious frames.

In 2018, Kenworth released the W990, a combination of their popular units–the W900, T680, and T880. Despite using a 12.8 liter Paccar MX-13 and a 14.9 liter Cummins X15, the W990 failed to match the W900 popularity.

The Missed Kenworth W900 Upgrade

While the Kenworth W900 models had various exterior, engine, and electrical upgrades, there’s at least one thing on the W900 that Kenworth never really upgraded, and that’s the HVAC box. Everyone that owns a W900 knows that the OEM blower motor is lackluster and the steel box is prone to corrosion. This is why Shoreline Truck Parts began building stainless steel Kenworth HVAC boxes with an upgraded blower motor.

Kenworth W900 HVAC Box

Stainless Kenworth W900 HVAC Boxes

Enjoy an Improved Kenworth W900 Today

You need an HVAC box that works as hard as you do, keeping you comfortable year-round. Our HVAC boxes are built right here in the USA, with 18 gauge 304 stainless steel. For extra strength, our boxes are spot welded instead of riveted, unlike most of our competitors.

To better meet your needs, we offer several models of the HVAC box, a Base model, a Standard model, and a Premium model (plug & play). If you’re tired of your inferior original equipment HVAC box, get a high-quality stainless steel Kenworth HVAC box today! Or, if you are in the market for other Kenworth W900 parts, you can find them here.

My cart
🎁 Only $50.00 away from free shipping to
Your cart is empty.

Looks like you haven't made a choice yet.