Identifying a Vintage Moxy Articulated Dump Truck

[MikePhua]

The Origins of Moxy and Its ADT Legacy
Moxy Engineering, founded in Norway in the 1960s, became a pioneer in articulated dump truck (ADT) design. Their early models were known for rugged construction, high flotation tires, and a unique center-mounted cab layout that improved visibility and balance. By the 1980s, Moxy had established itself as a serious competitor to Volvo and Caterpillar in the 25–30 ton ADT class, especially in European markets.
The company’s trucks were often used in quarrying, demolition, and infrastructure projects where maneuverability and traction were critical. Moxy’s design philosophy emphasized simplicity, mechanical durability, and off-road capability. In the early 2000s, Moxy was acquired by Doosan, but many of its legacy models remain in service today, particularly in the UK and Scandinavia.
Clues from the Field and Model Identification
A mystery Moxy truck spotted on a demolition site in England raised questions about its model designation. The truck was hauling broken concrete from a Hitachi EX455 excavator to a crusher pile. Based on visual cues—cab shape, body design, and tipping cylinder configuration—several possibilities emerged.
Candidate models:

• MT27: A mid-1990s model with a 25-ton payload, known for its single tipping cylinder and compact cab.
  
• 5200 or 5220: Older models from the 1980s, predating the MT-series, with more angular bodywork and mechanical simplicity.
  
• 6227S: A later model fitted with a Scania D9 engine, offering improved torque and fuel efficiency.
  

Terminology:

• Tipping Cylinder: A hydraulic actuator that lifts the dump body for material discharge.
  
• Payload Rating: The maximum weight of material the truck is designed to carry, excluding its own weight.
  

Operators familiar with the Volvo A25 noted similarities in size and layout, suggesting the Moxy in question was likely in the 25-ton class. The MT27 and 6227S both fit this profile, with the latter offering more refined engine performance and cab ergonomics.
Engine and Drivetrain Characteristics
The Scania D9 engine, commonly found in the 6227S, is a 9-liter inline-six diesel known for its torque curve and reliability. Paired with a ZF transmission and Moxy’s proprietary transfer case, the drivetrain delivers consistent traction across uneven terrain.
Key specs:

• Engine: Scania D9, approx. 300 hp
  
• Transmission: ZF 6-speed automatic
  
• Drive: 6x6 full-time with inter-axle differential lock
  
• Top speed: ~50 km/h unloaded
  

Terminology:

• Inter-Axle Differential Lock: A feature that locks the differential between axles to prevent wheel slip in low-traction conditions.
  
• Transfer Case: A gearbox that splits power between front and rear axles in all-wheel-drive systems.
  

In Norway, a contractor reported that his 6227S operated reliably in sub-zero temperatures and steep quarry grades, outperforming newer machines in terms of traction and fuel economy.
Cab Design and Operator Experience
Moxy’s cab design evolved significantly over the years. Early models featured minimal insulation and analog gauges, while later versions introduced ergonomic seating, improved visibility, and digital diagnostics. The MT27 and 6227S both offered center-mounted cabs, which balanced the truck’s weight and improved turning radius.
Cab features:

• Adjustable air-suspension seat
  
• Full visibility windshield with wiper coverage
  
• Analog tachometer and hydraulic pressure gauges
  
• Optional heater and defroster for cold climates
  

Terminology:

• Turning Radius: The minimum circular path a vehicle can navigate, critical for maneuvering in tight job sites.
  
• Air-Suspension Seat: A seat mounted on an air bladder system that absorbs shock and vibration.
  

A demolition crew in Scotland noted that the Moxy’s cab layout allowed better coordination with excavator operators, reducing cycle times and improving safety during concrete hauling.
Maintenance and Parts Availability
While Moxy trucks are known for durability, sourcing parts for older models can be challenging. The acquisition by Doosan led to some parts being discontinued or rebranded. However, many components—especially drivetrain and hydraulic parts—are shared with other European manufacturers.
Maintenance tips:

• Inspect tipping cylinder seals every 1,000 hours
  
• Replace hydraulic filters quarterly
  
• Monitor driveline U-joints for wear and vibration
  
• Use OEM or Scania-approved lubricants for engine and transmission
  

Terminology:

• U-Joint (Universal Joint): A flexible coupling in the driveline that allows angular movement between shafts.
  
• Hydraulic Filter: A component that removes contaminants from fluid to protect pumps and valves.
  

A fleet manager in Yorkshire reported that his team retrofitted a 6227S with aftermarket hydraulic lines and rebuilt the tipping cylinder using locally machined seals, extending the truck’s service life by five years.
Conclusion
Identifying a vintage Moxy ADT requires a blend of visual analysis, historical knowledge, and mechanical intuition. Whether it’s an MT27, a 5200-series, or the more refined 6227S, these trucks represent a legacy of Scandinavian engineering built for rugged terrain and demanding workloads. With proper maintenance and sourcing ingenuity, even decades-old Moxy units continue to haul, tip, and climb with confidence. In the world of articulated dump trucks, age doesn’t always mean retirement—it often means resilience.