Comparing the John Deere 605C and Caterpillar 939C Track Loaders

[MikePhua]

The Role of Track Loaders in Mid-Scale Earthmoving
Track loaders occupy a unique niche between dozers and wheel loaders, offering the traction of a crawler with the versatility of a bucket-equipped machine. They excel in soft ground, demolition, and grading tasks where rubber-tired machines struggle. In the 1990s and early 2000s, two standout models in this category were the John Deere 605C and the Caterpillar 939C—both designed for contractors needing compact power with rugged undercarriage performance.
While neither model is in current production, they remain active in fleets and auctions, valued for their mechanical simplicity and field serviceability.
Terminology Annotation

• Hydrostatic Drive: A transmission system using hydraulic fluid to transfer power from engine to tracks, allowing variable speed control without gear shifts.
  
• Loader Frame: The structural assembly supporting the lift arms and bucket, often integrated with the cab and undercarriage.
  
• Track Gauge: The distance between the centerlines of the tracks, influencing stability and maneuverability.
  
• Breakout Force: The maximum force the loader can exert to lift or pry material with the bucket.
  

John Deere 605C Overview
The 605C was part of Deere’s mid-size track loader lineup, powered by a 4-cylinder turbocharged diesel engine producing around 80 horsepower. It featured a hydrostatic transmission, joystick controls, and a sealed cab option. Its operating weight hovered near 16,000 lbs, with a bucket capacity of approximately 1.3 cubic yards.
Key specs:

• Engine: John Deere 4045T, turbocharged
  
• Transmission: Dual-path hydrostatic
  
• Bucket breakout force: ~18,000 lbs
  
• Track width: ~16 inches
  
• Lift capacity: ~6,000 lbs
  

Strengths:

• Smooth hydrostatic control for fine grading
  
• Simple mechanical layout for field repairs
  
• Good visibility from cab for trenching and finish work
  

Limitations:

• Limited parts availability due to model age
  
• Lower ground clearance compared to newer designs
  
• No factory joystick auxiliary hydraulics
  

In one grading crew in Ohio, a 605C was used for finish grading around foundations. The operator praised its smooth controls and predictable response, especially when feathering slopes near concrete forms.
Caterpillar 939C Overview
The 939C was Caterpillar’s answer to mid-size tracked versatility. Powered by a Cat 3046 engine producing around 90 horsepower, it featured a hydrostatic transmission, sealed undercarriage, and optional joystick controls. With an operating weight near 17,500 lbs and a bucket capacity of 1.5 cubic yards, it offered slightly more muscle than the Deere.
Key specs:

• Engine: Caterpillar 3046, turbocharged
  
• Transmission: Hydrostatic with electronic modulation
  
• Bucket breakout force: ~20,000 lbs
  
• Track width: ~18 inches
  
• Lift capacity: ~6,500 lbs
  

Strengths:

• Robust undercarriage with sealed rollers
  
• Stronger lift and breakout specs
  
• Better parts support through Cat dealer network
  

Limitations:

• Heavier footprint may cause rutting in soft soil
  
• More complex electronics in later variants
  
• Higher fuel consumption under load
  

In a demolition project in British Columbia, a 939C was used to clear debris and load trucks. The operator noted its aggressive breakout force and stable platform when working near uneven foundations.
Operational Comparison and Field Behavior
When comparing the two machines in real-world conditions:

• The 605C excels in finish grading and light material handling
  
• The 939C performs better in demolition, heavy loading, and rough terrain
  
• Both machines offer hydrostatic control, but Cat’s modulation system gives finer low-speed control
  
• Deere’s simpler layout makes it easier for small crews to maintain without dealer support
  

Suggested applications:

• 605C: Landscaping, trench backfill, pad grading
  
• 939C: Demolition, site clearing, truck loading
  

In a municipal fleet in Texas, both machines were used side by side. The 605C was favored for park trail grading, while the 939C handled storm debris removal.
Maintenance and Parts Support
Due to their age, parts availability is a key concern. Caterpillar maintains stronger aftermarket and dealer support, especially for undercarriage and hydraulic components. Deere parts may require sourcing through salvage yards or specialty rebuilders.
Maintenance tips:

• Inspect track tension weekly and adjust per manual
  
• Replace hydraulic filters every 500 hours
  
• Monitor hydrostatic fluid temperature during summer operation
  
• Use OEM-spec fluids to maintain pump integrity
  

Recommended upgrades:

• Install LED work lights for improved visibility
  
• Retrofit joystick auxiliary controls if hydraulics are available
  
• Add quick coupler for faster bucket changes
  

In one restoration project in New Zealand, a 605C was retrofitted with a modern seat and LED lighting, improving operator comfort and night grading capability.
Final Thoughts
The John Deere 605C and Caterpillar 939C represent two philosophies in mid-size track loader design—Deere’s simplicity and finesse versus Cat’s power and durability. Both machines continue to serve in the field, proving that well-built iron can outlast its production run. Choosing between them depends on task profile, parts access, and operator preference.
In the hum of hydrostatic drive and the bite of steel tracks, these loaders remind us that performance is not just horsepower—it’s how the machine fits the job.