Restoring and Operating the 1968 Case 310G Dozer

[MikePhua]

The Case 310G and Its Historical Significance
The Case 310G crawler dozer was introduced during a transformative era in construction machinery. Built by J.I. Case Company, which had already established itself as a pioneer in agricultural and industrial equipment since the mid-1800s, the 310G represented a compact solution for grading, land clearing, and light earthmoving. With a production run that spanned the late 1960s, the 310G was part of Case’s strategy to offer reliable, affordable machines to small contractors and municipalities.
Equipped with a 4-cylinder gasoline or diesel engine, the 310G delivered around 40 horsepower and featured a direct-drive transmission, mechanical steering clutches, and a manually operated blade. Its simplicity made it easy to maintain, and its size allowed it to work in tighter spaces than larger dozers. Though overshadowed by later hydrostatic models, the 310G remains a favorite among vintage equipment enthusiasts and rural landowners.
Terminology Clarification

• Crawler dozer: A tracked machine used for pushing soil, grading terrain, and clearing land.
  
• Steering clutch: A mechanical device that disengages one track to allow turning.
  
• Final drive: The gear assembly that transfers torque from the transmission to the tracks.
  
• Blade lift cylinder: A hydraulic actuator that raises and lowers the dozer blade.
  

Common Challenges in Operating Vintage Dozers
Owners of the Case 310G often face issues typical of aging machinery:

• Difficulty starting due to worn ignition components or fuel delivery problems
  
• Weak blade response from leaking hydraulic cylinders or low fluid levels
  
• Inconsistent steering caused by clutch wear or linkage misalignment
  
• Track tension problems leading to derailment or excessive wear
  
• Electrical faults from corroded wiring or outdated charging systems
  

A technician in Alberta restored a 310G that had sat idle for 12 years. After rebuilding the carburetor, replacing the spark plugs, and flushing the hydraulic system, the machine started reliably and performed light grading work without issue.
Mechanical Restoration and Parts Sourcing
Restoring a 310G requires patience and resourcefulness. Key steps include:

• Identifying the engine model and verifying compression and spark
  
• Replacing fuel lines, filters, and tank if contaminated
  
• Inspecting hydraulic hoses and cylinders for leaks or dry rot
  
• Rebuilding steering clutches with new friction discs and springs
  
• Replacing track pads and adjusting tension using the idler screw
  

Recommended components:

• SAE 30 engine oil for vintage gasoline engines
  
• AW32 hydraulic fluid for blade lift system
  
• OEM-style ignition coil and distributor cap
  
• Aftermarket track hardware compatible with Case undercarriage specs
  

A contractor in Georgia sourced clutch parts from a salvage yard and fabricated new linkage bushings. The result was smooth steering and improved control during slope work.
Hydraulic System Maintenance and Blade Control
The 310G’s blade is operated by a single or dual hydraulic cylinder setup, depending on configuration. To maintain blade responsiveness:

• Check fluid level and inspect for contamination
  
• Replace seals and wipers on lift cylinders
  
• Clean control valve and verify spool movement
  
• Bleed air from the system after repairs
  
• Use proper hydraulic fluid viscosity for ambient temperature
  

Tips:

• Avoid overloading the blade beyond rated capacity
  
• Use float mode when backdragging to reduce strain
  
• Inspect hoses for abrasion and secure with clamps
  
• Monitor blade angle and wear on cutting edge
  

A fleet manager in British Columbia added a pressure gauge to the hydraulic line, allowing operators to monitor blade force and prevent overextension.
Electrical System and Cold Start Strategy
Vintage dozers often suffer from unreliable electrical systems. Solutions include:

• Replacing battery with high CCA rating for cold starts
  
• Installing a modern alternator with internal regulator
  
• Upgrading wiring harness with marine-grade wire
  
• Adding a starter relay to reduce voltage drop
  
• Using a block heater or ether assist in cold climates
  

Operator tips:

• Clean battery terminals monthly and check ground connections
  
• Use a voltmeter to verify charging system output
  
• Avoid cranking for more than 10 seconds at a time
  
• Let engine idle briefly before shutdown to stabilize temperature
  

A crew in Texas retrofitted their 310G with a solar battery maintainer, reducing dead battery complaints during winter storage.
Steering and Undercarriage Reliability
The 310G uses mechanical steering clutches and brake bands to control track movement. To maintain maneuverability:

• Adjust clutch linkage for proper engagement
  
• Replace worn friction discs and inspect pressure plates
  
• Lubricate pivot points and control rods
  
• Inspect final drives for gear wear and oil leaks
  
• Maintain track tension and replace worn pads
  

Preventive measures:

• Grease track rollers and idlers monthly
  
• Avoid sharp turns at high speed to reduce clutch wear
  
• Keep track area free of debris and mud buildup
  
• Use track guards if operating in rocky terrain
  

A technician in Georgia rebuilt the steering clutch assembly using aftermarket discs and added a grease fitting to the linkage pivot, improving responsiveness and reducing operator fatigue.
Conclusion
The 1968 Case 310G dozer remains a testament to mechanical simplicity and durable design. With thoughtful restoration, disciplined maintenance, and respect for its limitations, this compact crawler can still perform meaningful work decades after leaving the factory. Whether grading a driveway, clearing brush, or shaping a pond bank, the 310G proves that old iron still has a place in modern land management. In the world of vintage equipment, reliability is earned through care—not just horsepower.