Komatsu DNH031_3M(S/N 41001-UP (D31S/Q/SM-20))
Maintenance schedule, common problems & OEM parts breakdown
The Komatsu DNH031-3M (S/N 41001-UP) is a medium-duty crawler bulldozer belonging to the D31 series lineage, specifically covering the D31S, D31Q, and D31SM configurations. This machine class typically operates in the 100-250 HP range with an operating weight suitable for mid-size earthmoving and grading tasks. The DNH031-3M succeeded earlier D31 variants and was eventually replaced by newer generations such as the DNH031-3L and DNH031-3K series. Configurations offered include straight tilt and angle dozer blades, catering to both general construction and specialized trimming applications.
Across the D31 series generations, Komatsu transitioned from older mechanical controls to more integrated hydraulic and electronic systems, improving fuel efficiency and operator comfort. The DNH031-3M remains relevant in the used and parts market due to its robust undercarriage design and widely available aftermarket support. Its modular powertrain and standardized hydraulic components make it a cost-effective option for fleet expansion or replacement, particularly in regions where Tier 4 emissions compliance is less stringent or where older machines are still actively deployed in mining and heavy civil works.
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 DNH031_3M(S/N 41001-UP (D31S/Q/SM-20)) specifications
Engine
| Model | SAA4D102E-2 |
| Type | Turbocharged, air-to-air aftercooled diesel |
| Net Power | 56 kW (75 HP) @ 2000 rpm |
Weights
| Operating Weight (D31EX) | 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
| Blade Type | Komatsu blade geometry (curvature optimized) |
| Blade Capacity | 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 your 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 DNH031_3M(S/N 41001-UP (D31S/Q/SM-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 DNH031_3M(S/N 41001-UP (D31S/Q/SM-20)) beyond the schedule
Predictive Maintenance & Fluid Analysis
Utilize KOWA oil analysis at every 500-hour interval to monitor engine wear metals and hydraulic contamination. Check coolant SCA levels at 500 hours to prevent liner cavitation in the D31-series engine. Monitor hydraulic oil particle counts to detect pump wear early. Track fuel dilution and soot levels in engine oil to determine optimal change intervals based on actual operating conditions rather than fixed schedules alone.
Corrective & Common Repairs
Address frequent hydraulic gear pump leaks common in the D31S/Q/SM-20 work equipment. Replace hydraulic return filters at 500 hours to protect pilot valves. Inspect and adjust track tension to prevent excessive undercarriage wear. Check final drive oil for water ingress, a common issue in wet conditions. Replace worn cutting edges and end bits to maintain blade efficiency and reduce strain on the push arms.
Overhaul & Rebuild Points
Plan engine overhaul around 10,000-15,000 hours depending on duty cycle. Inspect turbocharger blades and bearings at 10,000 hours for wear. Evaluate final drive planetary gears and seals at 15,000 hours for leakage. Check swing machinery and track chain elongation for replacement. Rebuild hydraulic pumps and motors when flow rates drop below specification or noise levels increase significantly.
Seasonal & Environment Servicing
In cold climates, use low-temperature hydraulic oil and check coolant freeze protection before winter. Clear debris from radiator and oil cooler fins frequently in dusty environments to prevent overheating. Inspect air filter restriction indicators more often in high-dust conditions. Use high-moisture fuel separators and drain water daily in humid environments. Grease all pivot points more frequently in abrasive or muddy conditions to prevent corrosion and binding.
DNH031_3M(S/N 41001-UP (D31S/Q/SM-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.
DNH031_3M(S/N 41001-UP (D31S/Q/SM-20)) fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| CA115 | Engine speed sensor and backup speed sensor failure | Faulty engine speed sensor, damaged wiring harness, or corroded connector at the sensor pin. | Inspect the engine speed sensor and wiring for damage; verify voltage at the pin connector and replace the sensor if necessary. |
| CA111 | Engine controller internal fault | Critical internal failure of the Electronic Control Module (ECM). | Replace or reprogram the ECM; verify power and ground connections to the controller. |
| CA441 | Battery voltage too low | Weak battery, failing alternator, or loose/corroded battery cables. | Check battery charge and condition; test alternator output and tighten all electrical connections. |
| CA442 | Battery voltage too high | Failing voltage regulator or alternator overcharging the system. | Test the alternator and voltage regulator; replace faulty components to prevent electrical damage. |
| AA10NX | Air cleaner clogging | Dirty or blocked air filter element restricting airflow. | Replace the air filter element; inspect the air intake system for obstructions. |
| B@BCNS | Engine coolant overheating | Low coolant level, failed thermostat, blocked radiator fins, or broken fan belt. | Check coolant level and inspect for leaks; clean radiator fins and verify fan belt tension. |
| B@HANS | Hydraulic oil overheating | Low hydraulic oil level, clogged hydraulic filter, or malfunctioning cooler fan. | Check hydraulic oil level and condition; replace the hydraulic filter and inspect the cooler fan operation. |
| CA122 | Intake air pressure sensor feedback voltage too high | Faulty intake air pressure sensor or short in the sensor wiring. | Verify the intake pressure sensor operation and inspect the wiring harness for shorts or damage. |
| CA123 | Intake air pressure sensor feedback voltage too low | Sensor short to ground, open circuit, or severe airflow restriction. | Check for sensor short circuits and inspect the air intake path for restrictions. |
| CA451 | Common rail pressure sensor feedback value too high | Faulty rail pressure sensor or actual overpressure condition in the fuel system. | Diagnose the fuel rail pressure sensor and inspect fuel pump lines for blockages or regulator issues. |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
DNH031_3M(S/N 41001-UP (D31S/Q/SM-20)) attachments & work tools
Blades
The DNH031_3M (S/N 41001-UP) is based on the D31S/Q/SM-20 platform, which utilizes a 75 hp (56 kW) SAA4D102E-2 engine and HST transmission. Specific blade types (S/SU/A) and VPAT availability for this exact serial range are not documented in the provided sources; typical widths and capacities vary by configuration/series.
Rippers
The DNH031_3M hydraulic system includes a dedicated hydraulic tank and filter specifically for the 3-point hitch or ripper attachment. The work equipment control lever for the 3-point hitch or ripper is a distinct component in the operator's compartment, indicating multi-shank ripper compatibility for this class.
Winches
The provided sources do not document winch class or towing winch options for the DNH031_3M. Specific towing winch configurations for this serial range are not available in the text.
Drawbars/Counterweights
The provided sources do not document specific drawbar or counterweight configurations for the DNH031_3M. Compatibility details for these components are not available in the text.
Cab/ROPS Guarding
The provided sources do not document specific cab or ROPS guarding options for forestry or waste configurations. Guarding details for this serial range are not available in the text.
Hydraulic Arrangement
The DNH031_3M uses a work equipment pump (part number 705-21-31020) to supply hydraulic fluid for front attachments. The hydraulic system includes a dedicated tank and filter for the 3-point hitch or ripper, with control managed by a specific work equipment control lever in the operator's compartment.
All DNH031_3M(S/N 41001-UP (D31S/Q/SM-20)) assemblies by section
Every catalogued assembly group for the Komatsu DNH031_3M(S/N 41001-UP (D31S/Q/SM-20)). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Guard
Komatsu : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-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 : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-20)) : Guard : Rear Cover And Hydraulic Tank (For 3-Point Hitch And Ripper) (For 4-Piller 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 : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-20)) : Guard : Rear Cover And Hydraulic Tank (With Rops Cab) (For 3-Point Hitch And P.T.O? 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 : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-20)) : Hydraulic System : Hydraulic Piping (Ripper And 3-Point Hitch 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 : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-20)) : Hydraulic System : Hydraulic Piping (Tank To Pump To Valve) (For 3-Point Hitch Or Ripper) (For Multi Purpose Bucket)(#41001-41183)
| 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 : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-20)) : Hydraulic System : Hydraulic Tank And Filter (For 3-Point Hitch Or Ripper)
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 6 |
| 01***35 | Bolt,(F4320-52a0 -5 ) | 5 |
| 01***16 | Bolt - Starting Motor Ground Cable | 2 |
Operator'S Compartment And Control System
Komatsu : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-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 : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-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 : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-20)) : Service Kit And Component Parts : 3-Point Hitch Cylinder
| 01***16 | Bolt, Battery To Frame Ground Wire Attaching | 1 |
| 01***26 | Nut,Nylon | 1 |
| 01***09 | Nut,(With Body Positioner) | 2 |
Komatsu : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-20)) : Service Kit And Component Parts : Control Valve (3-Spool) (1/2) (For 3-Point Hitch Or Ripper)
| 01***20 | Bolt (Itl) | 4 |
| 01***25 | Bolt, Seal Cover Mounting | 2 |
| 01***30 | Bolt | 6 |
Komatsu : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-20)) : Service Kit And Component Parts : Control Valve (3-Spool) (2/2) (For 3-Point Hitch Or Ripper)
| 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 ) | 2 |
Work Equipment
Komatsu : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-20)) : Work Equipment : 3-Point Hitch (1/2)
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 6 |
| 01***50 | Bolt,(For Tree Pusher) | 10 |
| 01***80 | Bolt,(For 100kg) | 6 |
Komatsu : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-20)) : Work Equipment : 3-Point Hitch (2/2)
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 6 |
| 01***38 | Nut | 2 |
| 01***30 | Washer, Spring (Supplied W/Spider Assembly), Washer-Spring | 6 |
Komatsu : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-20)) : Work Equipment : Drawbar (For 3-Point Hitch)
| 01***55 | Bolt,(With Hook) | 4 |
| 01***12 | Washer,(With Body Positioner) | 1 |
| 01***60 | Flat Washer - M20 (Hardened) | 4 |
Komatsu : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-20)) : Work Equipment : Hydraulic Piping (Valve To Cylinder) (For 3-Point Hitch)
| 01***20 | Bolt,(With Auto Emergency Steering) | 2 |
| 01***25 | Washer,Spring?For Additional Rear Lam | 2 |
| 01***23 | Washer, Wiring Harness Mounting Bracket | 2 |
Komatsu : Dnh031_3m(S/N 41001-Up (D31s/Q/Sm-20)) : Work Equipment : Swing Drawber (For 3-Point Hitch)
| 01***55 | Bolt,(With Hook) | 10 |
| 01***80 | Bolt,(For 100kg) | 4 |
| 01***60 | Flat Washer - M20 (Hardened) | 14 |
Frequently asked questions
What engine does the Komatsu DNH031-3M use?
The DNH031-3M (S/N 41001-UP) uses a Komatsu diesel engine from the D31 series family, specifically associated with the D31S, D31Q, and D31SM configurations. Exact engine model designation varies by region and emissions tier.
What is the operating weight of the Komatsu DNH031-3M?
Operating weight varies by configuration, series, and attachment package. It falls within the medium-duty bulldozer class, typically ranging between 20,000 and 60,000 lbs depending on track shoe width, counterweight, and blade type.
What replaced the Komatsu DNH031-3M?
The DNH031-3M was succeeded by newer generations in the DNH031 line, including the DNH031-3L and DNH031-3K series, which feature updated emissions compliance, improved hydraulics, and enhanced telematics integration.
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