Volvo A25C and Terex 2566C Offer Contrasting Approaches to Articulated Hauling

[MikePhua]

The Rise of Articulated Dump Trucks in Earthmoving
Articulated dump trucks (ADTs) revolutionized off-road hauling by combining high payload capacity with terrain adaptability. Introduced in the 1960s, the concept gained traction in mining, quarrying, and large-scale construction. By the 1990s, manufacturers like Volvo and Terex had refined their designs to balance power, maneuverability, and operator comfort.
The Volvo A25C and Terex 2566C represent two distinct philosophies in ADT engineering. Both are 25-ton class haulers, but they differ in drivetrain layout, suspension design, and long-term reliability. Understanding their strengths and limitations helps fleet managers choose the right machine for specific jobsite conditions.
Volvo Construction Equipment and the A25C Legacy
Volvo CE, founded in 1832 and headquartered in Sweden, pioneered the articulated hauler market with the DR 631 in 1966. The A25C, launched in the early 1990s, was part of Volvo’s third-generation ADT lineup. It featured:

• Payload capacity: 25 metric tons
  
• Engine: Volvo TD 73 KCE, ~255 hp
  
• Transmission: Volvo automatic with torque converter
  
• Drive: 6x6 with differential locks
  
• Suspension: Hydropneumatic front, bogie rear
  
• Top speed: ~50 km/h
  

The A25C was known for its smooth ride, responsive steering, and excellent traction in soft ground. Volvo’s emphasis on operator ergonomics and service access made it a favorite in rental fleets and long-term infrastructure projects.
Terex and the 2566C’s Mechanical Muscle
Terex, with roots tracing back to General Motors’ Euclid division, built its reputation on rugged, no-nonsense equipment. The 2566C was designed for durability and simplicity, often favored in mining and aggregate operations. Key specs include:

• Payload capacity: 25 metric tons
  
• Engine: Cummins 6CTA8.3, ~260 hp
  
• Transmission: ZF automatic or manual options
  
• Drive: 6x6 with mechanical transfer case
  
• Suspension: Leaf spring front, walking beam rear
  
• Top speed: ~45 km/h
  

The 2566C’s mechanical layout made it easier to repair in remote areas. Its robust frame and drivetrain could handle punishing loads, though at the cost of ride comfort and finesse.
Terminology Notes

• Articulated frame: A pivoting joint between cab and dump body, allowing tight turns and terrain flexibility.
  
• Hydropneumatic suspension: Uses gas and fluid to absorb shocks, improving ride quality.
  
• Walking beam: A rear axle design that balances load across uneven terrain.
  
• Differential lock: A feature that forces wheels to rotate together, improving traction in slippery conditions.
  

Operational Differences and Field Behavior
The Volvo A25C excels in:

• Soft ground and wet conditions
  
• Long haul cycles with frequent turns
  
• Operator comfort during extended shifts
  
• Fuel efficiency due to optimized drivetrain
  

The Terex 2566C performs best in:

• Rock quarries and hard-packed haul roads
  
• Short, repetitive dump cycles
  
• Environments with limited access to electronic diagnostics
  
• Cold climates where mechanical systems outperform electronics
  

Operators often describe the A25C as “smooth and forgiving,” while the 2566C is “tough and direct.” The Volvo’s cab layout and suspension reduce fatigue, whereas the Terex demands more physical engagement but offers raw durability.
A Story from the Canadian Shield
In 2006, a contractor in northern Ontario used both models on a dam expansion project. The Volvo A25C was assigned to haul clay across marshy terrain, while the Terex 2566C moved rock fill from a nearby quarry. After 18 months, the Volvo required fewer repairs but struggled with frame stress under heavy loads. The Terex endured harsher treatment but needed more frequent brake and transmission service. The fleet manager concluded, “Volvo wins on comfort, Terex wins on punishment.”
Maintenance and Parts Considerations
Volvo A25C:

• Electronic diagnostics simplify troubleshooting
  
• Parts availability strong through Volvo CE network
  
• Requires specialized tools for transmission service
  
• Hydropneumatic suspension needs periodic nitrogen recharge
  

Terex 2566C:

• Mechanical systems easier to repair in the field
  
• Parts availability varies by region and model year
  
• Manual transmission option reduces complexity
  
• Leaf springs and walking beams require regular bushing checks
  

Recommended service intervals:

• Engine oil: Every 250 hours
  
• Transmission fluid: Every 500 hours
  
• Brake inspection: Monthly
  
• Suspension components: Quarterly
  

Which Hauler Fits Your Operation
Choose based on priorities:

• Volvo A25C: Ideal for infrastructure, roadbuilding, and long-haul sites
  
• Terex 2566C: Best for mining, quarrying, and remote operations
  

For mixed fleets, the A25C offers better integration with modern telematics. For owner-operators in rugged terrain, the 2566C provides a lower-cost, high-durability solution.
Final Thoughts
The Volvo A25C and Terex 2566C reflect two paths in articulated hauler design—one focused on refinement, the other on resilience. Both machines have proven their worth across decades of hard work. Whether navigating muddy haul roads or climbing quarry grades, the choice between them depends not just on specs, but on the demands of the job and the philosophy of the crew behind the wheel.