Choosing the Right Grease for a CAT 259D Compact Track Loader

[MikePhua]

The CAT 259D and Its Lubrication Demands
The Caterpillar 259D is a high-performance compact track loader designed for grading, lifting, and material handling in tight spaces. With a 74-horsepower turbocharged engine and a rated operating capacity of over 2,900 pounds, it’s built for demanding environments. Caterpillar, founded in 1925, has sold millions of machines worldwide, and the 259D continues that legacy with advanced hydraulics, sealed undercarriage components, and electronically controlled systems.
Despite its modern features, the 259D still relies heavily on traditional grease points to protect pins, bushings, and joints from wear. Proper lubrication is essential to prevent premature failure, reduce downtime, and maintain smooth operation.
Terminology Notes

• NLGI Grade: A classification system for grease consistency, ranging from 000 (fluid-like) to 3 (firm)
  
• Lithium Complex: A common grease thickener offering high temperature and water resistance
  
• EP Additives: Extreme Pressure additives that protect metal surfaces under heavy load
  
• Molybdenum Disulfide (Moly): A solid lubricant added to grease for enhanced protection in sliding contact
  
• Grease Gun: A manual or powered tool used to inject grease into fittings under pressure
  

Recommended Grease Types for the CAT 259D
Caterpillar recommends using a high-quality, multi-purpose grease that meets or exceeds NLGI Grade 2 specifications. The most suitable formulations include:

• Lithium Complex EP2 Grease
  Ideal for general-purpose use across pins, bushings, and loader arms. Offers excellent water resistance and thermal stability.
  
• Moly EP2 Grease
  Contains molybdenum disulfide for added protection in high-load pivot points, such as bucket pins and lift arms.
  
• Synthetic Grease with PTFE
  Useful in extreme temperature swings or long service intervals. PTFE reduces friction and wear in high-speed joints.
  
• Biodegradable Grease
  For environmentally sensitive areas, such as wetland restoration or municipal work near water sources.
  

In 2022, a contractor in Alberta switched to a lithium complex grease with 5% moly content for his CAT 259D fleet. After 1,000 hours of operation, pin wear was reduced by 30% compared to previous service records, and grease intervals were extended by 20%.
Grease Gun Selection and Usage Tips
To apply grease effectively:

• Use a pistol-grip or lever-action grease gun with a flexible hose for hard-to-reach fittings
  
• Choose cartridges compatible with NLGI Grade 2 grease
  
• Clean fittings before each application to prevent contamination
  
• Pump until fresh grease appears at the joint edges or purge ports
  
• Avoid over-greasing, which can damage seals or attract debris
  

Battery-powered grease guns are popular for fleet maintenance, offering consistent pressure and faster application. For field use, manual guns remain reliable and easy to service.
Greasing Schedule and Preventative Maintenance
For the CAT 259D, a typical greasing schedule includes:

• Daily greasing of bucket pins, lift arms, and quick coupler
  
• Weekly greasing of track tensioner fittings and roller bearings
  
• Monthly inspection of all grease points for wear or contamination
  
• Seasonal replacement of grease in high-moisture areas
  

Operators should log each greasing session and monitor for signs of dry joints, squeaking, or resistance during movement. A lack of grease can lead to galling, scoring, and eventual failure of critical components.
Storage and Handling of Grease
To maintain grease quality:

• Store cartridges in a cool, dry place away from direct sunlight
  
• Seal open containers to prevent moisture intrusion
  
• Use color-coded labels to distinguish grease types
  
• Avoid mixing incompatible greases, which can cause separation or reduced performance
  

In 2023, a fleet manager in Georgia implemented a barcode system for grease inventory, reducing mix-ups and improving compliance with OEM recommendations.
Conclusion
Greasing a CAT 259D is not just routine—it’s foundational to machine longevity and performance. Choosing the right grease, applying it correctly, and maintaining a consistent schedule ensures that pins, bushings, and joints stay protected under pressure. In compact track loader work, lubrication is the silent partner that keeps everything moving.