CAT336GC

Not all “336” machines are the same. The series includes several distinct variants, each with different engines, power outputs, and target applications:

The 336D and 336D2 offer the lowest entry price but carry higher operating costs and older emissions technology. The 336F represents a step up in efficiency and power. The Next Gen 336 (introduced 2018) brings significant advances in fuel economy, technology, and maintenance intervals, while the 336 GC prioritizes low cost per hour for general construction applications.

For the current Next Gen 336, the core specifications are:

For the 336 GC variant, the operating weight is approximately 36,500 kg, with net power of 195 kW (261 hp). Bucket digging force is 196 kN (44,090 lbf), and stick digging force is 128 kN (28,780 lbf).

The engine options also differ by region. In some markets, the 336 is offered with the C7.1 TTA engine (225 kW) for Tier 4 Final / Stage V compliance. In others, the C9.3B engine (232 kW) remains available for higher power demands.

Fuel consumption is one of the most significant operating costs for any excavator. The 336 series has seen substantial improvements across generations:

• 336D / 336D2: Typical consumption of 19–25 L/h in standard conditions. Real-world heavy digging in rock or earthmoving pushes this to 30–36 L/h.

• 336F: Improved efficiency, with the Next Gen 336 delivering up to 15% higher fuel efficiency than the 336F in similar applications.

• Next Gen 336 (C9.3B): The Smart Mode feature automatically matches engine and hydraulic power to digging conditions, providing maximum power when needed and reducing power when not required. Combined with a demand-based hydraulic fan system, the Next Gen 336 achieves up to 15% fuel savings compared to previous models.

• 336 GC: Equipped with a C7.1 engine and Smart Mode, the 336 GC is approximately 5% more fuel efficient than the 336F in similar applications.

Operating cost benchmarks: Industry data suggests hourly fuel costs of approximately $30 USD for the 336, with monthly fuel costs around $1,000. Monthly maintenance costs are estimated at $2,000–$3,000 depending on usage intensity.

The CAT 336 is generally a robust machine, but several recurring issues have been documented by owners and technicians. Being aware of these can save thousands in unexpected repairs.

1. Hydraulic System Performance Degradation (High-Hour Machines). A documented case on a 336D with 16,000 hours described hydraulics becoming very slow after a few hours of operation, with performance returning after a 30-minute cool-down. The issue appeared when hydraulic oil temperature reached approximately 40°C. Potential causes include main pump wear, flow control solenoid valve issues, or controller problems.

2. Low Rail Pressure / Fuel System Issues. On 336 models with common rail fuel systems, low rail pressure during cranking is a known problem. One technician reported a machine achieving only 760 psi in the rail when 6,000 psi was required for proper starting. This can be caused by leaking injector seals, faulty pressure relief valves, or transfer pump failure. Using genuine Cat filters is critical—aftermarket filters often fail to maintain proper pressure.

3. Frequent Fuel Filter Restriction Events. Some 336 units with 9.3L engines experience fuel filter restriction codes every 150–200 hours. One owner reported that a missing center seal on the filter head during fuel/water separator replacement allowed unfiltered fuel to bypass the primary filter, prematurely clogging secondary filters.

4. Engine Power Loss. Potential causes include clogged air filters (replacement recommended every 500 hours), turbocharger air leaks (check bellows seal integrity), or injector solenoid valve failure requiring Cat ET diagnostic equipment.

5. Travel Deviation. Some owners report the machine pulling to one side during travel, often caused by a faulty travel motor or imbalance in the hydraulic circuit.

6. Undercarriage Wear. Track shoes, sprockets, rollers, and idlers are major wear items. Periodic undercarriage rebuilds can cost $8,000–$12,000 depending on conditions.

Long-term reliability note: One owner reported a CAT 336 running for nearly 15,000 hours with core components untouched, stating: “Attendance rate is our lifeline for making money, it holds up”. With proper maintenance, the 336 is capable of exceptional longevity.

Maintaining a CAT 336 to 5,000 hours requires routine servicing, wear-part replacement, and potentially major component work. Below is a realistic cost breakdown:

Estimated 5,000-hour cumulative maintenance cost: $18,000–35,000 USD

Maintenance cost reduction (Next Gen models): The Next Gen 336 offers extended maintenance intervals compared to the 336F. Engine oil and fuel filters are synchronized for service at 1,000 hours, reducing downtime. Compared to the 336D2, maintenance costs are reduced by up to 15%, and compared to the 336F, up to 20%. The 336 GC features ground-level access for hydraulic oil checks and fuel system water draining, simplifying daily inspections.