Restoring and Maintaining the International Harvester 500 Crawler

[MikePhua]

The Legacy of International Harvester Crawlers
International Harvester, founded in 1902 through the merger of several agricultural machinery companies, became a dominant force in both farming and construction equipment. By the mid-20th century, IH had expanded into tracked machines, offering compact crawlers for light-duty earthmoving, grading, and forestry work. The 500 series crawler was introduced in the 1960s as a smaller alternative to the larger TD models, targeting contractors, farmers, and municipalities needing maneuverable machines with solid pushing power.
The IH 500 crawler was built for simplicity and durability. With an operating weight around 10,000 pounds and a 4-cylinder diesel engine producing roughly 50 horsepower, it was ideal for clearing brush, grading driveways, and small-scale excavation. Its mechanical transmission and straightforward hydraulic system made it easy to repair in the field, which contributed to its popularity in rural areas across North America.
Core Specifications and Mechanical Features
Typical configuration of the IH 500 includes:

• Engine: IH D-155 diesel, 4-cylinder, naturally aspirated
  
• Horsepower: Approximately 50 hp at 2,200 rpm
  
• Transmission: 4-speed manual with high-low range
  
• Final drives: Planetary gear reduction
  
• Blade width: 6 to 7 feet (depending on configuration)
  
• Track gauge: ~50 inches
  
• Fuel capacity: 20 gallons
  

Terminology notes:

• Final drives: Gear assemblies at the ends of the drive axles that reduce speed and increase torque.
  
• Planetary gear: A gear system that distributes load across multiple gears, improving durability.
  
• Track gauge: The distance between the centerlines of the tracks, affecting stability and turning radius.
  

Common Issues and Restoration Challenges
Many IH 500 crawlers still in use today are over 50 years old. Restoration efforts often begin with addressing the following issues:

• Stuck steering clutches due to rust or oil contamination
  
• Worn track chains and sprockets
  
• Hydraulic leaks from blade lift cylinders
  
• Engine hard starting or excessive smoke
  
• Transmission gear wear or shifter linkage slop
  

In one case from rural Saskatchewan, a farmer acquired a 500 crawler that had sat idle for over a decade. The steering clutches were frozen solid, and the fuel system was clogged with algae. After soaking the clutches in penetrating oil and flushing the tank with biocide-treated diesel, the machine was brought back to life and used for fence line clearing.
Steering Clutch Diagnosis and Repair
The IH 500 uses dry steering clutches and brake bands to control track movement. These components are prone to seizing if the machine sits unused or if moisture enters the clutch housing.
Symptoms of clutch failure:

• Machine turns only in one direction
  
• Steering levers feel loose or offer no resistance
  
• Grinding noise during turns
  
• Brake band overheating
  

Recommended steps:

• Remove clutch housing covers and inspect for rust or oil
  
• Clean clutch discs with brake cleaner and emery cloth
  
• Adjust brake bands to factory spec (typically 1/8" clearance)
  
• Replace clutch springs if fatigued or broken
  

Terminology notes:

• Dry clutch: A friction-based clutch system not immersed in oil, more sensitive to contamination.
  
• Brake band: A curved friction surface that wraps around a drum to slow or stop rotation.
  

In Georgia, a contractor restored steering function by fabricating new clutch discs from industrial-grade friction material and machining them to fit. The original parts were no longer available, but the retrofit worked flawlessly.
Engine and Fuel System Rehabilitation
The D-155 engine is mechanically simple but sensitive to fuel quality and air intrusion. Common problems include:

• Injector pump wear
  
• Glow plug failure in cold weather
  
• Cracked fuel lines
  
• Dirty air filters reducing combustion efficiency
  

Maintenance tips:

• Replace fuel filters every 250 hours
  
• Bleed fuel system after filter changes
  
• Use block heaters in winter climates
  
• Clean air intake and check for rodent nests
  

In Vermont, a forestry crew found that their crawler wouldn’t start after sitting through winter. The glow plugs had failed, and the air intake was blocked by nesting material. After replacing the plugs and cleaning the intake, the engine started immediately.
Undercarriage and Track System Care
The undercarriage includes track chains, rollers, idlers, and sprockets. Neglect leads to rapid wear and poor traction.
Best practices:

• Check track tension monthly (ideal sag: 1 to 1.5 inches)
  
• Grease rollers every 100 hours
  
• Inspect sprocket teeth for rounding or chipping
  
• Replace track pads if cracked or bent
  

Terminology notes:

• Track sag: The vertical drop between the top of the track and the carrier roller, indicating tension.
  
• Carrier roller: A roller that supports the top of the track chain, reducing wear.
  

In Oregon, a logging operator extended track life by rotating pads every 1,000 hours and using graphite-based grease on rollers to reduce friction.
Blade and Hydraulic System Maintenance
The blade is mounted via a C-frame and controlled by hydraulic lift cylinders. Common issues include:

• Cylinder seal leaks
  
• Bent blade cutting edge
  
• Sluggish lift due to air in hydraulic lines
  
• Cracked welds on blade mounts
  

Solutions:

• Replace cylinder seals with Viton or nitrile kits
  
• Bleed hydraulic system after repairs
  
• Reinforce blade edges with bolt-on wear strips
  
• Inspect hoses for abrasion and replace as needed
  

In Pennsylvania, a municipal crew added a bolt-on snow edge to their crawler’s blade, allowing dual use for grading and winter road maintenance.
Parts Availability and Sourcing Strategies
While IH no longer produces crawler parts, many components are still available through:

• Salvage yards specializing in vintage IH equipment
  
• Cross-referencing with agricultural tractors using the same engine
  
• Hydraulic shops offering custom seal kits
  
• Online forums and regional co-ops
  

Recommended sourcing tips:

• Use engine serial number to match D-155 components
  
• Seek undercarriage parts from Berco or ITM equivalents
  
• Fabricate blade components locally if OEM parts are unavailable
  

In Alberta, a contractor rebuilt his crawler’s hydraulic cylinders using seals from a Case backhoe, matched by size and pressure rating.
Operator Stories and Field Wisdom
In Tennessee, a retired operator shared that his IH 500 had cleared over 100 acres of pastureland since 1975. Despite its age, the machine still ran daily thanks to meticulous maintenance and a rebuilt transmission.
In Chile, a mining crew used a restored IH 500 to grade access roads in mountainous terrain. Its compact size and mechanical simplicity made it ideal for narrow switchbacks, outperforming larger dozers in agility.
Conclusion
The International Harvester 500 crawler remains a symbol of rugged simplicity and mechanical resilience. Though parts may be scarce and repairs require ingenuity, the machine’s straightforward design makes it a favorite among restoration enthusiasts and rural contractors. With proper care, thoughtful upgrades, and a bit of field wisdom, the IH 500 can continue pushing dirt and carving grades for decades to come.