Komatsu DRT031_2J_E(S/N 42001-UP (D31A/AM/E-20))
Maintenance schedule, common problems & OEM parts breakdown
The Komatsu DRT031-2J-E (S/N 42001-UP) is a compact crawler bulldozer in the D31 series, designed for utility, landscaping, and light earthmoving applications. This specific serial range corresponds to the D31A/AM/E-20 configuration. The machine is powered by a Komatsu S6D102E-1 series engine, a water-cooled, direct-injection diesel unit meeting Tier 4 Final/Stage V emissions standards. Operating weight varies by configuration, typically ranging between 6,000 and 7,500 kg (13,200–16,500 lb) depending on blade type, counterweight, and undercarriage setup. The DRT031-2J-E succeeded earlier D31 variants and was part of the second-generation D31 line before being replaced by the D31EX and D31PX series. Configurations offered include straight tilt dozers, angle dozers, and low-ground-pressure (LGP) variants to suit different soil conditions.
Across the D31 series generations, Komatsu shifted from mechanical hydraulic controls to electro-hydraulic pilot systems, improving operator precision and reducing component wear. The DRT031-2J-E represents the transition to Tier 4 emissions compliance, integrating a Komatsu Diesel Particulate Filter (KDPF) and Selective Catalytic Reduction (SCR) system. This machine matters in the used and parts market because its compact size allows access to confined job sites where larger dozers cannot operate, while its S6D102E engine shares components with other Komatsu compact equipment, ensuring parts availability. The DRT031-2J-E’s modular design and standardized fluid specifications make it a cost-effective option for municipal and agricultural fleets seeking reliable, low-profile earthmoving capability.
Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.
Komatsu DRT031_2J_E(S/N 42001-UP (D31A/AM/E-20)) specifications
Engine
| Model | SAA4D102E-2 |
| Type | Turbocharged, air-to-air aftercooled diesel |
| Net Power | 56 kW (75 HP) @ 2000 rpm |
| Emissions Tier | Tier 4 Final / EU Stage V |
Weights
| Operating Weight (D31EX Config) | 7130 kg (15,720 lb) |
Dimensions
| Transport Length | Not documented for this exact serial range — verify with your dealer |
| Transport Width | Not documented for this exact serial range — verify with your dealer |
| Transport Height | Not documented for this exact serial range — verify with your dealer |
| Track Gauge | Not documented for this exact serial range — verify with your dealer |
| Ground Clearance | Not documented for this exact serial range — verify with your dealer |
Performance
| Travel Speed (Forward) | Not documented for this exact serial range — verify with your dealer |
| Travel Speed (Reverse) | Not documented for this exact serial range — verify with your dealer |
| Drawbar Pull | Not documented for this exact serial range — verify with your dealer |
| Gradeability | Not documented for this exact serial range — verify with your dealer |
| Ground Pressure | Not documented for this exact serial range — verify with your dealer |
Blades
| Standard Blade Type | S/SU/A/VPAT (varies by configuration/series) |
| Blade Capacity | Not documented for this exact serial range — verify with your dealer |
| Blade Width | Not documented for this exact serial range — verify with your dealer |
Service Capacities
| Fuel Tank | Not documented for this exact serial range — verify with your dealer |
| Hydraulic System | Not documented for this exact serial range — verify with dealer |
| Engine Oil | Not documented for this exact serial range — verify with your dealer |
| Cooling System | Not documented for this exact serial range — verify with your dealer |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
Komatsu DRT031_2J_E(S/N 42001-UP (D31A/AM/E-20)) maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
Servicing the DRT031_2J_E(S/N 42001-UP (D31A/AM/E-20)) beyond the schedule
Predictive Maintenance & Fluid Analysis
Utilize KOWA fluid analysis at every 500-hour interval to monitor engine wear metals and hydraulic contamination. Check coolant SCA concentration at 500 hours to prevent liner cavitation in the S6D102E-1 engine. Monitor hydraulic oil particle count to detect pump or valve wear early. Use KOMTRAX telematics to track load frequency and engine hours, ensuring timely sampling. Analyze transmission oil for gear wear indicators at 1,000 hours. Track DEF consumption rates to identify SCR system efficiency issues before fault codes appear.
Corrective & Common Repairs
Address hydraulic hose leaks promptly, especially at high-pressure lines to the work equipment pump. Replace fuel filters at 500 hours to protect the common-rail injection system. Inspect and replace worn track shoes and sprockets to maintain proper tension and reduce undercarriage stress. Check blade cutting edge bolts for torque loss due to vibration. Replace air filter elements when the restriction indicator shows clogging. Inspect the KDPF for soot loading and perform regeneration cycles as needed to prevent exhaust backpressure issues.
Overhaul & Rebuild Points
Plan engine overhaul around 10,000–12,000 hours, focusing on piston rings, valve seats, and turbocharger bearings. Rebuild hydraulic pumps and motors when flow rates drop below specification or internal leakage is detected. Inspect final drive gears and bearings at 5,000 hours for pitting or wear. Check swing machinery and track rollers for excessive play or noise. Evaluate the torque converter for clutch wear and oil contamination. Replace all seals and gaskets during major service intervals to prevent fluid leaks and maintain system pressure.
Seasonal & Environment Servicing
In cold climates, use low-temperature hydraulic oil and ensure DEF is stored above freezing. Check coolant antifreeze concentration before winter to prevent engine block cracking. In dusty environments, inspect air filters more frequently and clean radiator fins daily to prevent overheating. In wet or muddy conditions, check track tension and undercarriage for mud buildup that can cause premature wear. Grease all pivot points more often in abrasive conditions. Monitor hydraulic fluid viscosity changes due to temperature extremes and adjust service intervals if necessary.
DRT031_2J_E(S/N 42001-UP (D31A/AM/E-20)) common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 113-60-43321 | Cartridge,Hydraulic Oil Filter (D31s) | Hydraulic service | Check fitment → |
| 07002-03334 | O-Ring, At Transmission Filter | Scheduled service item | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
DRT031_2J_E(S/N 42001-UP (D31A/AM/E-20)) fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| CA115 | Engine crankshaft speed sensor failure | Broken sensor, wiring issue, or connector corrosion | Replace the speed sensor and verify the voltage at the pin connector |
| CA111 | Internal engine controller fault | ECM hardware or software failure | Replace or reprogram the ECM |
| CA451 | Common rail pressure sensor feedback value too high | Malfunction in the rail sensor or actual overpressure condition | Diagnose the fuel rail pressure sensor or pump lines |
| CA441 | Battery voltage too low | Weak battery, failing alternator, or loose connections | Replace the alternator or battery; check the voltage regulator |
| CA442 | Battery voltage too high | Faulty voltage regulator or alternator overcharging | Replace the alternator or battery; check the voltage regulator |
| CA122 | Intake air pressure high voltage | Sensor malfunction or airflow restriction | Verify the intake pressure sensor and wiring |
| CA123 | Intake air pressure low voltage | Sensor short or airflow restriction | Check for a sensor short or an airflow restriction |
| CA153 | Intake air temperature sensor error (high voltage) | Faulty IAT sensor | Replace or test the IAT sensor |
| CA154 | Intake air temperature sensor error (low voltage) | Faulty IAT sensor | Replace or test the IAT sensor |
| CA234 | Engine overspeed | Throttle calibration error, engine load cycle issue, or operator misuse | Verify throttle calibration, engine load cycle, or operator misuse |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
DRT031_2J_E(S/N 42001-UP (D31A/AM/E-20)) attachments & work tools
Blades
The D31A/AM/E-20 series supports standard (S), semi-universal (SU), and all-purpose (A) blade configurations, with VPAT availability varying by configuration and series. Typical widths and capacities for this class range from 2.41 m (7 ft 11 in) to 3.05 m (10 ft) width, with blade capacities between 1.5 m³ (2.0 cu yd) and 2.4 m³ (3.1 cu yd), varying by configuration/series.
Rippers
Multi-shank rippers are the standard option for this class, with single-shank variants available for specific soil conditions. Weights for ripper assemblies in this class typically range from 1,200 kg (2,646 lbs) to 1,800 kg (3,968 lbs), varying by configuration/series.
Winches
Class-appropriate towing winches for the D31 series are rated for loads up to 50 kN (11,240 lbs) with cable capacities of 100 m (328 ft). These winches are typically mounted to the rear drawbar and require specific hydraulic flow rates, varying by configuration/series.
Drawbars/Counterweights
Rear drawbars are configured for standard hitch pins and include provisions for counterweight mounting to balance ripper or winch loads. Counterweight options for this class typically add 800 kg (1,764 lbs) to 1,500 kg (3,307 lbs) to the rear, varying by configuration/series.
Cab/ROPS Guarding
Forestry and waste configurations require FOPS/ROPS certified cabs with additional side and rear guard kits to protect against falling debris. These guarding options typically add 150 kg (331 lbs) to the overall machine weight, varying by configuration/series.
Hydraulic Arrangement
Front and rear tools utilize a dual-circuit hydraulic system with priority flow to the dozer blade and auxiliary flow to attachments. Hydraulic connections for rippers and winches are located at the rear frame, with flow rates varying by configuration/series.
All DRT031_2J_E(S/N 42001-UP (D31A/AM/E-20)) assemblies by section
Every catalogued assembly group for the Komatsu DRT031_2J_E(S/N 42001-UP (D31A/AM/E-20)). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Guard
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Guard : Rear Cover And Hydraulic Tank (3-Point Hitch? P.T.O. And Ripper) (Noise Suppression For Ec)(#42001-42414)
| 01***25 | Bolt,Without Revolution Sensor | 3 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 20 |
| 01***40 | Bolt,R.H. Outside And L.H. Inside, Bolt | 4 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Guard : Rear Cover And Hydraulic Tank (3-Point Hitch? P.T.O. And Ripper) (Regulation Of Eu Dynamic Noise)(#42415-)
| 01***16 | Bolt (With Air Heater & Conditioner) | 2 |
| 01***25 | Bolt,Without Revolution Sensor | 3 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 20 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Guard : Rear Cover And Hydraulic Tank (For 3-Point Hitch And Ripper) (For 2-Pillar Type Canopy)
| 01***25 | Bolt,Without Revolution Sensor | 3 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 20 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 2 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Guard : Rear Cover And Hydraulic Tank (For 3-Point Hitch And Ripper) (For 4-Pillar Type Canopy)
| 01***25 | Bolt,Without Revolution Sensor | 3 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 20 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 2 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Guard : Rear Cover And Hydraulic Tank (With Rops Cab) (3-Point Hitch? P.T.O. And Ripper)
| 01***25 | Bolt,Without Revolution Sensor | 3 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 20 |
| 01***40 | Bolt,R.H. Outside And L.H. Inside, Bolt | 4 |
Hydraulic System
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Hydraulic System : Hydraulic Piping (3-Point Hitch Or Ripper Cylinder Line) (Chassis Side)
| 01***20 | Bolt, Wiring Harness Mounting Bracket | 3 |
| 01***09 | Nut,(With Body Positioner) | 4 |
| 01***25 | Washer,Spring?For Additional Rear Lam | 1 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Hydraulic System : Hydraulic Piping (Tank To Pump To Valve) (For 3-Point Hitch Or Ripper)(#42001-42722)
| 01***40 | Bolt,(With Air Conditioner) | 4 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 1 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 4 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Hydraulic System : Hydraulic Tank And Filter (For 3-Point Hitch Or Ripper)
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 3 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 3 |
| 01***35 | Bolt,(F4320-52a0 -5 ) | 5 |
Operator'S Compartment And Control System
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Operator'S Compartment And Control System : Work Equipment Control Lever (1/2) (For 3-Point Hitch Or Ripper)
| 01***16 | Bolt - Seat And Tether Belt Mounting | 4 |
| 01***25 | Bolt,(Rear Attachment Less) | 1 |
| 01***30 | Bolt - M8 X 30lg | 3 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Operator'S Compartment And Control System : Work Equipment Control Lever (2/2) (For 3-Point Hitch Or Ripper)
| 01***25 | Bolt,(Rear Attachment Less) | 6 |
| 01***05 | Nut,L.H. (For Trimming Dozer) | 1 |
| 01***06 | Nut,(With Back-Up Alarm) (Op), Nut; Was 01580-10806 | 1 |
Service Kit And Component Parts
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Service Kit And Component Parts : Control Valve (3-Spool) (1/2) (For Trimming And Ripper) (For China)
| 01***20 | Bolt (Itl) | 4 |
| 01***25 | Bolt, Seal Cover Mounting | 2 |
| 01***30 | Bolt | 6 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Service Kit And Component Parts : Control Valve (3-Spool) (2/2) (For Trimming And Ripper) (For China)
| 07***34 | O-Ring, O-Ring, Oil Level And Fill Plug | 3 |
| 07***34 | O-Ring, At Transmission Filter | 1 |
| 70***61 | O-Ring,(Pc100ss) | 1 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Service Kit And Component Parts : Control Valve (4-Spool) (1/3) (For 3-Point Hitch Or Ripper)(#42001-42722)
| 01***20 | Bolt (Itl) | 4 |
| 01***25 | Bolt, Seal Cover Mounting | 4 |
| 01***30 | Bolt (Itl) | 2 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Service Kit And Component Parts : Control Valve (4-Spool) (1/3) (For 3-Point Hitch Or Ripper)(#42723-)
| 01***12 | Bolt | 4 |
| 01***25 | Screw | 4 |
| 01***30 | Bolt | 2 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Service Kit And Component Parts : Control Valve (4-Spool) (2/3) (For 3-Point Hitch Or Ripper)(#42001-42722)
| 01***20 | Bolt (Itl) | 2 |
| 01***30 | Bolt | 6 |
| 07***30 | Ring, Seal - Between Sections | 2 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Service Kit And Component Parts : Control Valve (4-Spool) (2/3) (For 3-Point Hitch Or Ripper)(#42723-)
| 01***12 | Bolt | 2 |
| 01***30 | Screw | 6 |
| 07***38 | O-Ring, (Without Emergency Steering) | 2 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Service Kit And Component Parts : Control Valve (4-Spool) (3/3) (For 3-Point Hitch Or Ripper)(#42001-42722)
| 07***34 | O-Ring, O-Ring, Oil Level And Fill Plug | 3 |
| 07***34 | O-Ring, At Transmission Filter | 1 |
| 07***34 | O-Ring,(F2310-59a0 -4 ) | 1 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Service Kit And Component Parts : Control Valve (4-Spool) (3/3) (For 3-Point Hitch Or Ripper)(#42723-)
| 07***34 | O-Ring, O-Ring, Oil Level And Fill Plug | 2 |
| 07***34 | O-Ring, At Transmission Filter | 1 |
| 07***34 | O-Ring,(F2310-59a0 -4 ) | 1 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Service Kit And Component Parts : Ripper Cylinder
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 1 |
| 01***24 | Nut,Bearing | 1 |
| 01***32 | Washer,(With Auto Emergency Steering) | 1 |
Work Equipment
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Work Equipment : Hydraulic Piping (Ripper Cylinder Line)
| 07***06 | Hose,(D21s) (Tbg Spec.) | 2 |
| 07***15 | Nut,(For Shipping And Storage) | 2 |
| 07***12 | Plug,(For Shipping And Storage) | 2 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Work Equipment : Ripper
| 01***20 | Bolt,(For Mono Lever Steering) | 2 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 3 |
| 01***30 | Bolt,(Not Used When Towing Winch) | 4 |
Komatsu : Drt031_2j_e(S/N 42001-Up (D31a/Am/E-20)) : Work Equipment : Ripper (For Trimming Dozer) (For China)
| 01***20 | Bolt,(For Mono Lever Steering) | 2 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 3 |
| 01***25 | Bolt,(Without Rops Guard? Canopy) | 4 |
DRT031_2J_E(S/N 42001-UP (D31A/AM/E-20)) serial number reference
The PIN plate is located on the front frame casting, typically on the operator's left side near the radiator support. Read the prefix as the first 10 characters (e.g., DRT031-2J-E) followed by the serial number starting at 42001 for this generation.
| Prefix | Identifies | Notes |
|---|---|---|
| DRT031-2J-E | DRT031-2J-E | S/N 42001-UP (D31A/AM/E-20). Factory parts catalog confirms this prefix covers the D31A/AM/E-20 engine family. No further serial breaks documented for this specific prefix in the provided source text. Verify with dealer for configuration-specific sub-ranges. |
Frequently asked questions
What engine does the Komatsu DRT031-2J-E use?
The Komatsu DRT031-2J-E (S/N 42001-UP) uses the Komatsu S6D102E-1 series engine, a water-cooled, direct-injection diesel unit meeting Tier 4 Final/Stage V emissions standards.
What is the operating weight of the Komatsu DRT031-2J-E?
The operating weight varies by configuration, typically ranging between 6,000 and 7,500 kg (13,200–16,500 lb) depending on blade type, counterweight, and undercarriage setup.
What model replaced the Komatsu DRT031-2J-E?
The DRT031-2J-E was part of the second-generation D31 line and was succeeded by the D31EX and D31PX series bulldozers.
What DRT031_2J_E(S/N 42001-UP (D31A/AM/E-20)) owners discuss
What are the typical powertrain and hydraulic behaviors for the Komatsu DRT031_2J_E(S/N 42001-UP (D31A/AM/E-20))?
What undercarriage and wear patterns are typical for this machine type?
What are the common engine quirks per series for the DRT031_2J_E(S/N 42001-UP (D31A/AM/E-20))?
What are the common electrical and sensor issues for this model?
What should be checked when buying a used DRT031_2J_E(S/N 42001-UP (D31A/AM/E-20))?
How should hydraulic system weakness be diagnosed?
What safety-critical fixes are associated with this machine?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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