Komatsubulldozersmall ( - d39)

Komatsu DWT037_1B_E1(S/N 42001-UP (D31E-20))

Maintenance schedule, common problems & OEM parts breakdown

The Komatsu DWT037-1B-E1 (S/N 42001-UP, D31E-20) is a small crawler bulldozer designed for light construction and site development. It belongs to the D31 series lineage, succeeding earlier D31A and D31P variants. Operating weights vary by configuration, typically ranging from 13,800 to 15,500 lbs (6,260 to 7,030 kg). The machine is equipped with a Komatsu S4D102E-1 engine, delivering approximately 81 hp (60 kW). Configurations include standard and low-ground-pressure (LGP) tracks, with options for various blade and ripper attachments.

Across the D31 series generations, changes focused on emissions compliance and undercarriage durability. The D31E-20 variant represents the Tier 4 Interim/Stage IIIA emissions package, integrating a Diesel Particulate Filter (KDPF) and Selective Catalytic Reduction (SCR) system compared to the pre-emissions D31A/AM models. This machine remains relevant in the used market due to its compact size, ease of maintenance, and widespread availability of aftermarket undercarriage parts. The D31E-20 is succeeded by the D31P-20A series, which further refined emissions controls and operator comfort.

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 DWT037_1B_E1(S/N 42001-UP (D31E-20)) specifications

Engine

ModelD31E-20
Emissions TierTier 4 Final / EU Stage V

Weights

Operating Weightvaries by configuration/series

Dimensions

Transport Lengthvaries by configuration/series
Transport Widthvaries by configuration/series
Transport Heightvaries by configuration/series
Track Gaugevaries by configuration/series
Track Shoe Widthvaries by configuration/series
Ground Clearancevaries by configuration/series

Performance

Travel Speed (Forward)varies by configuration/series
Travel Speed (Reverse)varies by configuration/series
Drawbar Pullvaries by configuration/series
Gradeabilityvaries by configuration/series
Ground Pressurevaries by configuration/series

Blades

Standard Blade Capacityvaries by configuration/series
SU Blade Capacityvaries by configuration/series
Angle Blade Capacityvaries by configuration/series
VPAT Blade Capacityvaries by configuration/series

Service Capacities

Fuel Tankvaries by configuration/series
Hydraulic Systemvaries by configuration/series
Engine Oilvaries by configuration/series
Cooling Systemvaries by configuration/series

Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.

Komatsu DWT037_1B_E1(S/N 42001-UP (D31E-20)) maintenance schedule

Service intervalTasks
Every 10 h
  • Check engine oil level and condition.
  • Check hydraulic fluid level via sight glass.
  • Check coolant level and ensure cap is secure.
  • Drain water from fuel separator.
  • Check DEF level.
  • Inspect air filter restriction indicator.
Every 250 h
  • Change engine oil and filter.
  • Grease all blade, ripper, and pivot points.
  • Check hydraulic fluid level.
  • Inspect air filter outer element.
  • Inspect belts and hoses for wear.
  • Perform visual walk-around inspection.
Every 500 h
  • Replace fuel filter.
  • Replace hydraulic return filter.
  • Test battery and load alternator.
  • Test coolant SCA concentration.
  • Collect KOWA engine oil sample.
  • Measure undercarriage wear.
Every 1,000 h
  • Collect hydraulic oil sample.
  • Change final drive oil (both sides).
  • Inspect turbocharger.
  • Check valve adjustment.
  • Perform structural inspection.
  • Check ROPS bolt torque.
Every 2,000 h
  • Change hydraulic oil.
  • Flush and replace coolant.
  • Service transmission/torque converter.
  • Perform comprehensive component evaluation.
  • Check KDPF status.
  • Check SCR system status.

Servicing the DWT037_1B_E1(S/N 42001-UP (D31E-20)) beyond the schedule

Predictive Maintenance & Fluid Analysis

Utilize Komatsu Oil Wear Analysis (KOWA) 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 S4D102E-1 engine. Monitor KDPF differential pressure and SCR DEF levels via KOMTRAX telematics to predict regeneration needs and avoid exhaust system damage. Track undercarriage wear measurements at 500 hours to forecast track and sprocket replacement timing.

Corrective & Common Repairs

Address frequent S4D102E-1 engine issues by inspecting fuel injectors and turbocharger hoses for leaks. Replace hydraulic return filters at 500 hours to prevent valve spool wear in the main control valve. Check final drive oil for water ingress and metal shavings at 1,000 hours. Inspect track tension and idler seals regularly to prevent premature undercarriage failure. Replace worn cutting edges and end bits to maintain blade efficiency and reduce chassis stress.

Overhaul & Rebuild Points

Plan engine overhaul around 10,000-12,000 hours based on compression testing and oil consumption trends. Inspect transmission clutch packs and torque converter at 10,000 hours for slippage or overheating signs. Rebuild final drives if oil analysis shows high gear wear metals or if noise indicates bearing failure. Check swing circle and pivot points for wear on attached implements. Evaluate hydraulic pump swash plates and cylinder seals for pressure loss during major service intervals.

Seasonal & Environment Servicing

In cold climates, use Komatsu Super Coolant AF-NAC and ensure DEF fluid is stored above freezing. Check battery electrolyte levels and charge state frequently in low temperatures. In dusty environments, clean air filter outer element more often and check restriction indicator daily. In wet conditions, inspect track adjusters and idler seals for mud packing and corrosion. Flush cooling system annually to prevent scale buildup in the radiator and oil cooler cores.

DWT037_1B_E1(S/N 42001-UP (D31E-20)) common service parts

Part numberPart
07000-02080O-Ring,Hydraulic Oil FilterCheck fitment →
195-13-13420FilterCheck fitment →

Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.

DWT037_1B_E1(S/N 42001-UP (D31E-20)) fault codes & troubleshooting

CodeMeaningLikely causeWhat to do
E10Engine controller power failure or engine control drive system circuit malfunction.Faulty ECM power connections, blown fuses, or damaged ground wires.Inspect ECM power connections, fuses, and ground wires.
CA115Engine crankshaft speed sensor and backup speed sensor failure.Broken sensor, wiring issue, or connector corrosion.Replace the speed sensor and verify voltage at the pin connector.
CA441Battery voltage too low.Weak battery, failing alternator, or loose connections.Replace the battery or alternator and check the voltage regulator.
CA442Battery voltage too high.Failing voltage regulator or alternator overcharging.Replace the alternator or battery and check the voltage regulator.
AA10NXAir cleaner clogging.Dirty or blocked air filter element.Replace the air filter element.
CA122Intake air pressure sensor feedback voltage too high.Faulty intake pressure sensor or wiring short.Verify the intake pressure sensor operation and inspect wiring.
CA123Intake air pressure sensor feedback voltage too low.Sensor short circuit or severe airflow restriction.Check for a sensor short or an airflow restriction.
CA144Coolant temperature sensor feedback voltage too high.Faulty coolant temperature sensor or open circuit.Replace the coolant temperature sensor.
CA145Coolant temperature sensor feedback voltage too low.Faulty coolant temperature sensor or short circuit.Replace the coolant temperature sensor.
CA451Common rail pressure sensor feedback value too high.Malfunctioning rail pressure sensor or actual overpressure condition.Diagnose the fuel rail pressure sensor or check pump lines.

Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.

DWT037_1B_E1(S/N 42001-UP (D31E-20)) attachments & work tools

Blades

The DWT037_1B_E1 (S/N 42001-UP, D31E-20) is classified as a 'Bulldozer - Small' and is compatible with standard, semi-universal, and angle blade configurations. VPAT (Variable Position Angle Tilt) blade availability is not documented for this specific serial range in the provided sources. Typical widths and capacities for this class vary by configuration and series.

Rippers

Multi-shank and single-shank ripper options are available for the D31 class bulldozers, with specific MS ripper listings confirming compatibility with Komatsu D31 models. Weights for these ripper attachments are not specified in the provided documentation.

Winches

Towing winch options are listed as a standard attachment category for Komatsu bulldozers in the provided equipment guides. Specific class ratings or capacities for the DWT037_1B_E1 are not detailed in the available text.

Drawbars/Counterweights

Drawbars and counterweights are included in the general list of Komatsu bulldozer attachments. Specific weights or compatibility details for the DWT037_1B_E1 are not provided in the source material.

Cab/ROPS Guarding

Forestry and waste configuration guarding options are not explicitly detailed for the DWT037_1B_E1 in the provided sources. The DWT037_1B-E7 (S/N 3001-UP) parts manual lists 'GUARD' as a component section, but specific forestry ROPS configurations for the E1 series are not documented.

Hydraulic Arrangement

The DWT037_1B_E1 utilizes a hydraulic system for front and rear tool operation, as indicated by the 'HYDRAULIC SYSTEM' section in the related DWT037 parts manual. Specific arrangement notes for front/rear tool connectivity are not provided in the source text.

All DWT037_1B_E1(S/N 42001-UP (D31E-20)) assemblies by section

Every catalogued assembly group for the Komatsu DWT037_1B_E1(S/N 42001-UP (D31E-20)). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.

Work Equipment
Komatsu : Dwt037_1b_e1(S/N 42001-Up (D31e-20)) : Work Equipment : Fair Lead (For Towing Winch)
01***25Bolt,(Without Rops Guard? Canopy)8
01***40Bolt,(With Center Guard)4
01***40Stud4
See all parts with full part numbers in Heavy Parts AI →
Komatsu : Dwt037_1b_e1(S/N 42001-Up (D31e-20)) : Work Equipment : Logging Arm (For Towing Winch)
01***25Bolt,(Without Rops Guard? Canopy)6
01***30Bolt,(Not Used With Emergency Str.)2
01***40Bolt,(With Center Guard)8
See all parts with full part numbers in Heavy Parts AI →
Komatsu : Dwt037_1b_e1(S/N 42001-Up (D31e-20)) : Work Equipment : Towing Winch (Bevel Gear? Drum And Wire Rope)
01***30Bolt,(Not Used With Emergency Str.)2
01***35Bolt, Bolt, Mount Tubes To Switch And Work Pumps12
01***35Bolt,R.H. Outside And L.H. Inside12
See all parts with full part numbers in Heavy Parts AI →
Komatsu : Dwt037_1b_e1(S/N 42001-Up (D31e-20)) : Work Equipment : Towing Winch (Bevel Pinion And Shift Fork)
01***30Bolt,(For Mechanical Governor)1
01***22Bolt8
01***30Bolt,(For Quick Shift) (Mitsubishi)2
See all parts with full part numbers in Heavy Parts AI →
Komatsu : Dwt037_1b_e1(S/N 42001-Up (D31e-20)) : Work Equipment : Towing Winch (Control Valve)
01***25Bolt,Without Revolution Sensor2
01***55Bolt,(10m)3
01***60Bolt,(For Japan And Sweden)3
See all parts with full part numbers in Heavy Parts AI →
Komatsu : Dwt037_1b_e1(S/N 42001-Up (D31e-20)) : Work Equipment : Towing Winch (Transmission Case)
01***25Bolt,Without Revolution Sensor3
01***35Bolt,(For Position Fixing)2
01***70Bolt (Op)4
See all parts with full part numbers in Heavy Parts AI →
Komatsu : Dwt037_1b_e1(S/N 42001-Up (D31e-20)) : Work Equipment : Towing Winch (Winch Case)
01***20Bolt,(With Auto Emergency Steering)4
01***30Bolt,(Not Used With Emergency Str.)30
01***40Bolt,(With Service Valve R.H.)2
See all parts with full part numbers in Heavy Parts AI →
Komatsu : Dwt037_1b_e1(S/N 42001-Up (D31e-20)) : Work Equipment : Towing Winch (Winch Pump)
01***55Bolt,(10m)5
01***70Bolt (Op)2
01***06Nut,(With Back-Up Alarm) (Op), Nut; Was 01580-108061
See all parts with full part numbers in Heavy Parts AI →
Komatsu : Dwt037_1b_e1(S/N 42001-Up (D31e-20)) : Work Equipment : Towing Winch (Winding Clutch 1/2)
01***30Bolt,(For Mechanical Governor)3
01***30Bolt,(For Quick Shift) (Mitsubishi)2
01***25Washer,Spring?For Additional Rear Lam3
See all parts with full part numbers in Heavy Parts AI →
Komatsu : Dwt037_1b_e1(S/N 42001-Up (D31e-20)) : Work Equipment : Towing Winch (Winding Clutch 2/2)
01***20Bolt,(With Auto Emergency Steering)6
01***35Bolt, Bolt, Mount Tubes To Switch And Work Pumps3
01***70Bolt1
See all parts with full part numbers in Heavy Parts AI →
Komatsu : Dwt037_1b_e1(S/N 42001-Up (D31e-20)) : Work Equipment : Towing Winch Control Lever
01***20Bolt,(With Auto Emergency Steering)4
01***25Bolt,Without Revolution Sensor2
01***30Bolt,(For Mechanical Governor)4
See all parts with full part numbers in Heavy Parts AI →
Komatsu : Dwt037_1b_e1(S/N 42001-Up (D31e-20)) : Work Equipment : Towing Winch Control Linkage
01***20Bolt,(With Auto Emergency Steering)2
01***30Bolt,(For Mechanical Governor)2
01***16Bolt, Battery To Frame Ground Wire Attaching3
See all parts with full part numbers in Heavy Parts AI →

Frequently asked questions

What engine does the DWT037-1B-E1 use?

The DWT037-1B-E1 (S/N 42001-UP, D31E-20) is powered by a Komatsu S4D102E-1 diesel engine, delivering approximately 81 hp (60 kW).

What is the operating weight of the DWT037-1B-E1?

Operating weight varies by configuration and attachment package, typically ranging from 13,800 to 15,500 lbs (6,260 to 7,030 kg).

What model replaced the DWT037-1B-E1?

The DWT037-1B-E1 was succeeded by the DWT037-1B-P1 (S/N 45001-UP, D31P-20A) series, which features updated emissions controls and improved operator comfort.

What DWT037_1B_E1(S/N 42001-UP (D31E-20)) owners discuss

What are the typical powertrain and hydraulic behaviors for the Komatsu DWT037_1B_E1(S/N 42001-UP (D31E-20)) bulldozer?
The machine utilizes a hydraulic system where performance degrades noticeably when oil warms up due to decreased viscosity, exposing internal leakage in pumps, control valves, or cylinders. If all functions (blade, dozer, travel) become slow simultaneously, the issue typically stems from a common source such as low hydraulic oil level, incorrect oil specification, clogged hydraulic filters, or engine RPM loss under load. If only one function is slow, the main pump is less likely the cause; instead, inspect the specific cylinder, control valve spool, or pilot control input for that circuit. The engine and hydraulic systems are closely linked; if engine RPM drops heavily when hydraulics are engaged, the hydraulic system may be placing excessive load on the engine or the engine cannot produce expected power. Conversely, if engine speed remains normal but movements weaken, the hydraulic system is the primary suspect. The machine relies on Komatsu EO, TO, and AXO fluid specifications for proper operation. Have your dealer verify hydraulic pressure settings for this serial range.
What undercarriage and wear patterns are typical for this machine type?
Undercarriage wear is accelerated by continuous load, dust exposure, and temperature extremes. Track tension must be monitored regularly; if the track repeatedly loosens, inspect the tensioner and undercarriage components. When the machine pulls to one side or travels faster on one side, check mechanical conditions first: track tension on both sides, mud or debris packed into the undercarriage, roller condition, and track-chain condition. If mechanical resistance is similar but one track consistently runs slower, hydraulic or final-drive diagnosis becomes relevant. Test the symptom in both forward and reverse directions to confirm if the same side remains weak. Final drive noise often indicates low oil levels or contamination. Have your dealer verify final drive oil levels and contamination status.
What are the engine quirks per series for the Komatsu DWT037_1B_E1(S/N 42001-UP (D31E-20))?
Engine performance issues dominate serious problems, including loss of power, increased fuel usage, or overheating. These may signal airflow restriction, injector wear, or failing fuel delivery components. If the engine loses power under digging load, check basic restrictions first: air-filter condition, fuel filters, fuel tank venting, intake hoses, and charge-air hoses on turbocharged engines for loose clamps or damaged pipes. If the machine stopped starting immediately after a filter replacement, check the recent work before assuming high-pressure component failure. Engine overheating during heavy work may indicate material packed between heat exchangers (radiator, hydraulic oil cooler, charge-air cooler, A/C condenser). If temperature rises during heavy work but falls when idling, cooling capacity may be marginal. If coolant is repeatedly expelled or the system becomes highly pressurized shortly after a cold start, deeper engine diagnosis is required. Have your dealer verify engine timing and injector calibration for this series.
What are common electrical and sensor issues for this machine?
The machine relies heavily on electronic control systems; therefore, a single faulty sensor or unstable power supply can trigger multiple warning signals. Owners report intermittent starting, dashboard failure, or machines that randomly shut down. Common electrical checks include battery state of charge, battery terminals, engine and chassis grounds, main starter cable, starter relay, and control circuit. A battery can show acceptable voltage until the starter is loaded; if the display dims heavily or voltage collapses during starting, perform a load and voltage-drop test. Fault codes such as CA441 (Battery Voltage Low Error) and CA442 (Battery Voltage High Error) indicate charging system issues. Codes like CA111 (Engine Controller Internal Fault) or CA342 (Calibration Code Incompatibility) suggest electronic control unit problems. Multiple fault codes often point to battery, grounds, or connectors. Have your dealer verify ECM calibration and sensor wiring integrity.
What should be checked when buying a used Komatsu DWT037_1B_E1(S/N 42001-UP (D31E-20))?
Verify the exact serial-prefix specification sheet and installed attachment package, as configurations affect weight, reach, fuel use, and transport planning. Check the hydraulic system for cold versus hot performance: test all functions cold and hot to identify internal leakage that worsens with temperature. Inspect the undercarriage for track tension, roller condition, and track-chain wear; test travel in both forward and reverse to detect side-specific weaknesses. Verify engine performance under load by monitoring RPM drop during hydraulic engagement and checking for black smoke or power loss. Inspect the cooling package for packed debris between heat exchangers. Check for intermittent fault codes related to sensors, ECM, or charging systems. Confirm fluid levels and conditions for engine oil, hydraulic oil, and coolant. Have your dealer verify the machine's specific serial range specifications and attachment package details.

Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.

Need a specific DWT037_1B_E1(S/N 42001-UP (D31E-20)) part?

Search live OEM part data, check fitment, and cross-reference alternatives with Heavy Parts AI.