Reviving a Legendary Kenworth C500 for Logging Duty

[MikePhua]

A Truck with Alaskan Heritage and Custom Engineering
The Kenworth C500 acquired by a seasoned logger in Washington State is no ordinary spare truck—it’s a piece of custom-built history. Originally one of three units brought down from Alaska, this particular C500 was engineered by Bill Paulson of McPaul Cat and Crane, a name well known in the Pacific Northwest for building extreme-duty rigs. While Paulson’s iconic yellow truck is widely recognized, this unit was originally built for Mike Plaas and later changed hands.
The truck features a 25,000-pound steer axle paired with a 25,000-pound Bendix Skagit drop axle, making it a formidable platform for heavy hauling. It has since been upgraded with 46,000-pound Rockwell drive axles sourced from Mack trucks, equipped with a 6.14 gear ratio and double lockers—ideal for traction in steep, muddy terrain. With a 224-inch wheelbase and a Big Cam 400 Cummins engine, the truck was designed to pull hard and survive abuse.
Terminology and Component Notes
- Drop Axle: An auxiliary axle that can be lowered to distribute load, often used in logging and heavy haul applications.
- Double Lockers: Differential locks on both axles, allowing full traction across all drive wheels.
- Brownie Box: A secondary transmission, often a 3- or 4-speed auxiliary gearbox used to multiply gear options.
- Big Cam 400: A 14-liter Cummins diesel engine known for its mechanical simplicity and torque output, popular in 1980s heavy trucks.
- 20918B Transmission: An 18-speed Eaton Fuller gearbox, offering a wide range of ratios for both highway and off-road use.
Transmission Failure and Upgrade Strategy
On its first trip under new ownership, the original 9-speed transmission failed—a common risk when pushing older drivetrains under load. Rather than repair the outdated gearbox, the owner sourced a 20918B 18-speed to pair with the existing 4-speed Brownie. This combination offers unmatched flexibility, especially in logging operations where terrain varies from steep grades to soft ground.
The auxiliary transmission, identified as a 1241 twin countershaft unit, is being retained. This setup allows gear splitting and torque multiplication, giving the operator control over speed and power delivery in challenging conditions. The decision to keep the Brownie reflects a philosophy shared by many veteran loggers: more gears mean more control, and more control means fewer broken parts.
Sourcing and Supply Chain Challenges
With new Kenworth trucks delayed due to factory backlogs and Cummins engine shortages, the decision to rebuild and upgrade an older unit is both practical and strategic. The owner noted that his new truck order may not arrive until the following year, prompting him to consider importing another C500 from Canada or fully restoring the current rig.
This reflects a broader trend in the industry. Supply chain disruptions have led many operators to invest in used equipment, especially models with proven mechanical reliability. In some cases, older trucks are being retrofitted with modern components, blending legacy durability with updated performance.
Operational History and Restoration Context
The truck spent most of its working life near Morton, Washington, before relocating to Redmond for several years. It was known in logging circles and had a reputation for toughness. A photo from its earlier days shows it stationed at the Kapowsin camp, still bearing the marks of hard use.
Now back on the road, the truck is being prepared for active duty. The owner’s new shop and yard are operational, though he notes the need for a skilled mechanic—a sentiment echoed across the industry as experienced technicians retire and replacements grow scarce.
Customization and Future Plans
Suggestions from fellow operators include adding stainless steel or chromium air intake stacks to give the truck a more aggressive look. With its rugged build and distinctive profile, the truck is already earning nicknames like “King of the C500s” and “Redd Fox of the C500s,” a nod to its character and lineage.
Plans for further upgrades may include:

• Replacing worn suspension bushings and torque rods
  
• Installing LED lighting and modern gauges
  
• Rebuilding the cab interior for comfort and noise reduction
  
• Adding hydraulic assist steering for better maneuverability
  
• Upgrading the cooling system for sustained heavy load operation
  

Kenworth’s C500 Legacy and Market Impact
The Kenworth C500 was introduced in the 1970s as a severe-service platform for oilfield, mining, and logging applications. Built on a reinforced frame with modular options, it could be configured for everything from winch trucks to off-road haulers. Its popularity in Alaska and the Pacific Northwest stemmed from its ability to handle extreme loads and terrain.
Though not produced in high volumes compared to highway models like the W900, the C500 earned a cult following among operators who valued strength over style. Many units are still in service today, often rebuilt multiple times and passed between owners who understand their worth.
Conclusion
This well-used Kenworth C500 isn’t just a spare truck—it’s a testament to mechanical resilience, thoughtful upgrades, and the legacy of custom-built logging rigs. With a new transmission, double lockers, and a seasoned operator at the helm, it’s ready to tackle the steep grades and muddy landings of the Pacific Northwest once again. In an era of delayed deliveries and electronic complexity, sometimes the best solution is steel, gears, and grit.