Komatsu D85A-12 Dozer Reliability and Market Realities

[MikePhua]

Komatsu’s Global Footprint and the D85 Legacy
Komatsu Ltd., founded in 1921 in Japan, has long been a dominant force in the heavy equipment industry. With a reputation for building durable, high-performance machinery, Komatsu expanded aggressively into international markets during the 1970s and 1980s. The D85 series dozers were part of this expansion, designed to compete directly with Caterpillar’s D7 and D8 models.
The D85A-12, a mid-sized crawler dozer, was introduced in the late 1970s and remained in production through the early 1990s. It was widely used in pipeline construction, forestry, and site preparation. While exact production numbers are hard to verify, industry estimates suggest that tens of thousands of D85 units were sold globally, with a significant portion entering North America through both official and unofficial channels.
Understanding Gray Market Machines
One of the most critical distinctions in the Komatsu D85A-12 lineage is the presence of gray market units—machines originally built for overseas markets but later imported into North America outside of Komatsu’s official distribution network. These machines often share core components with domestic models but may differ in electrical systems, safety features, and part compatibility.
Operators who purchase gray market dozers often face challenges sourcing parts. While major components like brake bands, steering clutches, and transmission rebuild kits may be available, smaller items—such as lens covers, gauges, and electrical switches—can be elusive. Dealers may need to fax Komatsu Japan for part numbers, introducing delays due to time zone differences and translation issues.
Engine Variants and Performance Profiles
The D85A-12 was commonly equipped with a Cummins NH220 engine, a naturally aspirated inline-six diesel known for its reliability and simplicity. However, field modifications were not uncommon. Some units were retrofitted with NTC blocks, boosting horsepower to 330 HP. While this upgrade increased pushing power, it also introduced stress on the drivetrain and cooling systems.
Key engine specs for the NH220 include:

• Displacement: 855 cubic inches (14.0 liters)
  
• Power output: Approx. 220 HP at 2100 RPM
  
• Torque: 740 lb-ft at 1500 RPM
  
• Fuel system: Mechanical direct injection
  

Operators appreciated the NH220 for its straightforward maintenance and parts availability. However, when modified beyond factory specs, the engine’s lifespan could be compromised, especially if cooling upgrades were not implemented.
Evaluating Hour Meters and Wear Indicators
Used dozers often present misleading hour meter readings. A machine showing 900.4 hours may appear lightly used, but without service records, such numbers are speculative. The last digit typically represents tenths of an hour, but faded gauges and replaced panels can distort accuracy. Industry veterans suggest assuming a minimum of 20,000 hours for any dozer over 30 years old unless proven otherwise.
Wear indicators to assess include:

• Undercarriage condition: Track links, rollers, and sprockets
  
• Hydraulic leaks: Especially around blade lift cylinders
  
• Transmission response: Smooth shifting under load
  
• Oil consumption: Excessive use may signal internal wear
  

One operator in Manitoba noted that his D85A-12 had no visible leaks and ran smoothly, but he remained cautious due to the machine’s age and uncertain history.
Parts Availability and Dealer Support
Despite its age, many parts for the D85A-12 remain available through Komatsu’s dealer network. Brake bands, steering clutches, sprockets, and transmission components are still listed for certain serial numbers. However, parts catalogs often exclude gray market machines, requiring manual lookup or direct communication with Komatsu Japan.
Aftermarket suppliers also play a role. Some companies specialize in sourcing OEM and aftermarket parts from overseas, often at lower prices than local dealers. These suppliers can be invaluable for hard-to-find items, provided the buyer has accurate part numbers.
Operational Experience and Field Feedback
Operators who’ve run the D85A-12 describe it as a solid performer with few quirks. One veteran from Connecticut recalled using the machine for a year in pipeline work, praising its weight and traction. He noted that while the dozer was “a little tired,” it had no major mechanical issues and was comfortable to operate.
Another contractor in Pennsylvania emphasized the importance of choosing machines common to the local market. He preferred Caterpillar’s D8H due to the availability of parts and dealer support. He warned that downtime caused by unavailable parts could outweigh the initial savings of buying a gray market Komatsu.
Recommendations for Buyers and Owners
For those considering a Komatsu D85A-12, especially a gray market unit, here are practical recommendations:

• Verify serial number and cross-check with Komatsu’s official import records
  
• Inspect undercarriage thoroughly; replacement costs can exceed $20,000
  
• Confirm engine type and check for unauthorized modifications
  
• Test transmission and steering clutches under load
  
• Establish a relationship with a dealer or aftermarket supplier familiar with Komatsu legacy machines
  

If the machine is intended for personal use or low-hour seasonal work, the risks may be manageable. However, for commercial operations, reliability and parts access are paramount.
Conclusion
The Komatsu D85A-12 remains a respected workhorse in the dozer world, especially among operators who value mechanical simplicity and raw pushing power. Its legacy is complicated by the presence of gray market units, which can introduce logistical challenges but also offer cost-effective solutions for experienced buyers.
With proper inspection, realistic expectations, and a solid support network, the D85A-12 can still deliver value decades after its production ceased. It stands as a testament to Komatsu’s engineering and the enduring appeal of machines built to last.