Champion 720 Motor Grader Identification and Transmission Troubleshootin

[MikePhua]

The Champion 720 and Its Evolution
The Champion 720 motor grader was part of Champion’s 700 Series lineup, which debuted in 1975 under the Series I designation. Champion Road Machinery Limited, based in Goderich, Ontario, had long been a respected name in the grader industry, known for building machines tailored to municipal and contractor needs. The 700 Series introduced articulated frames and a range of powertrain options, including Allis-Chalmers and Cummins engines, paired with transmissions from Gearco and Clark.
By 1984, Champion launched Series II, standardizing the engine to Cummins and introducing the Gearco 8400 powershift transmission. This shift simplified parts support but created confusion for machines built during the transitional years. Series III followed in 1989, featuring improved hydraulics, visibility, and Duramide bearings on the circle and moldboard slide. U.S. production sometimes retained older configurations longer than Canadian models, leading to hybrid machines with mixed features.
Decoding Serial Numbers and Cab Features
Serial numbers on Champion graders follow a structured format that can reveal production year and configuration. For example, a unit labeled 720-056-101-1918-2 likely belongs to the Series I or early Series II range. The presence of a slanted windshield and single side glass behind the door suggests a Series II cab, but drivetrain components may still reflect earlier design choices.
Terminology annotation:

• Series I/II/III: Generational designations used by Champion to denote major upgrades in frame, powertrain, and cab design.
  
• Articulated frame: A chassis design allowing the grader to bend in the middle for tighter turns and improved maneuverability.
  

Machines from the mid-1980s often featured a control pedestal with three levers: Forward-Neutral-Reverse, gear selection (1-2-3), and High-Low range. The absence of a clutch pedal and the presence of these levers suggest a semi-automatic transmission, possibly a Gearco 9150 or Clark 28000, rather than the later 8400 powershift.
Diagnosing Transmission Issues
One common issue with older Champion 720 graders is failure to engage forward or reverse. This can stem from several causes:

• Low transmission fluid levels
  
• Disconnected or broken shift linkages
  
• Internal wear in the transmission valve body
  
• Faulty shifter cables or control rods
  
• Pressure loss due to worn seals or pump failure
  

Terminology annotation:

• Valve body: A hydraulic control unit that directs fluid to engage gears in automatic or semi-automatic transmissions.
  
• Drop case: A secondary gearbox mounted below the main transmission, often used to alter gear ratios or drive direction.
  

To check fluid levels, locate the level plugs on the passenger side of the drop case. These should be inspected while the engine is running. If fluid is present and clean, the next step is to verify that the shift linkages are properly connected. On Gearco 9150 units, the shifter cable mounts to the control valve mid-transmission. A broken or misaligned cable can prevent gear engagement entirely.
Evaluating Engine and Transmission Pairings
The Allis-Chalmers 3500 engine, while functional, is generally considered less desirable than the Cummins options found in later models. The 3500 is a naturally aspirated diesel with limited parts availability and lower torque output compared to the Cummins 6BT or 6CT series.
Terminology annotation:

• Naturally aspirated: An engine that draws air without forced induction, resulting in lower power density.
  
• Torque output: The rotational force produced by the engine, critical for pushing and grading operations.
  

If the transmission is severely damaged, replacement may be impractical unless a donor unit is available. Gearco and Clark transmissions are no longer widely supported, and sourcing parts can be difficult. In some cases, operators have retrofitted newer transmissions or converted machines to manual gearboxes, though this requires significant fabrication.
Restoration Considerations and Use Cases
For owners acquiring Champion 720 graders at scrap value, restoration may be feasible for light-duty use such as driveway grading or snow removal. Machines with intact frames, hydraulics, and blade assemblies can be revived with modest investment if the engine and transmission are serviceable.
Recommended steps include:

• Flushing and replacing all fluids
  
• Inspecting hydraulic cylinders and hoses
  
• Rebuilding or replacing shifter linkages
  
• Installing pressure gauges to monitor transmission health
  
• Verifying blade articulation and circle rotation
  

Terminology annotation:

• Circle rotation: The ability of the grader blade to rotate horizontally, allowing angled cuts and ditch shaping.
  
• Articulation joint: The pivot point in the frame that enables steering through bending rather than wheel turning.
  

For grading a shared driveway, even a partially restored Champion 720 can outperform smaller tractors or skid steers, especially in snow or clay-rich soil. However, resale value may be limited unless the machine is fully functional and cosmetically restored.
Historical Footnote and Production Variants
Champion’s decision to offer multiple powertrain combinations in Series I created long-term service challenges. Machines built in South Carolina sometimes featured unique configurations not found in Canadian production. This included hybrid control layouts and non-standard transmissions. By 1988, most graders had transitioned to standardized Cummins-Gearco pairings, but earlier units remain in circulation with mixed features.
Terminology annotation:

• Hybrid configuration: A machine built with components from different production eras or suppliers, often complicating maintenance.
  
• Standardization: The process of unifying parts and systems across models to simplify manufacturing and support.
  

Collectors and operators interested in vintage graders often seek out Series I and early Series II machines for their mechanical simplicity and rebuild potential. While parts sourcing can be difficult, the machines themselves are robust and capable of decades of service with proper care.
Conclusion
The Champion 720 motor grader represents a transitional era in construction equipment, blending mechanical reliability with evolving hydraulic and transmission systems. Identifying the correct series and drivetrain is essential for effective troubleshooting and restoration. Whether used for personal grading projects or as part of a vintage fleet, the 720 remains a testament to Champion’s engineering legacy—durable, adaptable, and still pushing dirt long after its production line shut down.