Evaluating the Komatsu D31S Track Loader for Mountain and Farm Use

[MikePhua]

The Komatsu D31S and Its Historical Footprint
The Komatsu D31S track loader belongs to a lineage of compact crawler loaders developed by Komatsu Ltd., a Japanese manufacturer founded in 1921. Komatsu began producing crawler tractors in the 1950s and expanded into track loaders by the 1970s, aiming to compete with Caterpillar and John Deere in the North American and European markets. The D31S series was designed as a mid-size loader with a general-purpose (GP) bucket, suitable for grading, logging, and light excavation. With an operating weight of around 16,000 lbs and a power output of approximately 60–70 hp depending on the variant, the D31S became a popular choice for small contractors and farm owners.
By the late 1990s, Komatsu had sold thousands of D31S units globally, with strong adoption in rural areas where simplicity and mechanical reliability were prized. The D31S-20, one of the later models, featured joystick steering and improved operator ergonomics, making it more intuitive for users transitioning from wheeled loaders or tractors.
Assessing Value and Condition in Used Units
When evaluating a used D31S, several key factors influence its market value:

• Undercarriage (UC) wear percentage
  
• Engine hours and maintenance history
  
• Hydraulic cylinder condition
  
• Bucket linkage and pin wear
  
• Paint and structural integrity
  
• Presence of ROPS (Roll Over Protective Structure) and PTO (Power Take-Off)
  

A well-maintained unit with 80–90% UC remaining, original paint, and tight controls can command a premium. In one case, a 1999 D31S-20 with 3,500 verified hours, joystick steering, and minor cylinder leaks was appraised at $20,000. After negotiation and minor repairs, the final sale price was $19,500—considered fair given the machine’s condition and rarity.
Comparing Alternatives in the Same Class
Buyers often compare the D31S to similar models from other manufacturers:

• John Deere 455G: Comparable in size and power, with better parts availability in North America
  
• Caterpillar 933C: Slightly heavier, known for robust hydraulics and resale value
  
• John Deere 555G: Larger footprint, tipping the scales over 20,000 lbs, better suited for heavy-duty work
  

While the D31S is ideal for mountainous terrain and light forestry tasks, the 455G offers a similar balance of power and agility with broader dealer support. The 555G, though more capable, may be overkill for small property owners and harder to maneuver on narrow trails.
Market Pricing Trends and Dealer Behavior
Used equipment pricing often reflects more than just mechanical condition. Dealers may list machines at inflated prices to test buyer interest, especially in regions with limited inventory. For example:

• D31S listed at $24,000
  
• 455G listed at $23,500 (rental unit, 70% UC)
  
• 933C available under $20,000
  

Buyers should expect to negotiate aggressively. Offering $18,000–$20,000 for a clean D31S is reasonable, especially if the machine has low hours and minimal wear. Auction prices for similar units often fall between $17,000 and $19,500, but lack the assurance of inspection or warranty.
Application Suitability for Mountain Properties
The D31S excels in environments where traction, stability, and compact size are critical. Its track system allows it to climb steep grades and traverse uneven terrain with minimal soil disturbance. For tasks like dragging logs, building trails, and clearing brush, the D31S offers:

• Low ground pressure for soft or muddy conditions
  
• Sufficient breakout force for small stumps and debris
  
• Maneuverability in tight forest paths
  
• Compatibility with winches or PTO-driven implements
  

One Virginia landowner selected the D31S specifically for its ability to navigate wooded slopes while maintaining a light footprint. After testing larger machines, he found the D31S to be the best compromise between power and agility.
Mechanical Observations and Maintenance Notes
Common wear points on the D31S include:

• Bucket roll pins and bushings
  
• Lift cylinder seals
  
• Track tensioners and sprockets
  
• Hydraulic filter housings
  

In the case of the 1999 unit mentioned earlier, the bucket roll cylinders began leaking slightly during initial use. The seller agreed to repack the cylinders and discount the price by $500 to account for pin wear. These repairs are typical for machines of this age and can be addressed with standard seal kits and basic tools.
Joystick steering, introduced in later models, offers smoother control and reduces operator fatigue. Users familiar with older lever systems often praise the upgrade, especially during long grading sessions.
Recommendations for First-Time Buyers
For those entering the track loader market, especially for personal land use:

• Prioritize machines with verified service history and low hours
  
• Inspect undercarriage components thoroughly—replacement costs are high
  
• Test hydraulic responsiveness and check for leaks under load
  
• Negotiate based on auction benchmarks and regional inventory
  
• Consider hiring an independent appraiser for high-value purchases
  
• Avoid impulse buys based solely on paint or dealer reputation
  

A buyer who pays slightly more for a clean, tight machine often saves in the long run by avoiding hidden repairs and downtime.
Conclusion
The Komatsu D31S remains a reliable and capable track loader for property owners and small contractors. While alternatives like the 455G and 933C offer competitive features, the D31S stands out for its balance of size, power, and terrain adaptability. With careful inspection and negotiation, first-time buyers can secure a machine that delivers years of dependable service—especially when matched to the demands of mountain land and forestry work.