Komatsu DDM020-5M-21(S/N 60001-UP (D21PG-6))
Maintenance schedule, common problems & OEM parts breakdown
The Komatsu DDM020-5M-21 is a compact crawler bulldozer designed for light-duty earthmoving and grading. It falls within the small dozer category, featuring an operating weight range of approximately 8,000 to 9,000 lbs (3,629 to 4,082 kg) depending on the specific configuration. The machine is part of the D20/D21 series lineage, which succeeded earlier D-series models and was eventually replaced by newer generations like the D21PG-6. Configurations offered include standard and low-ground-pressure (LGP) variants, with options for various blade types and ripper attachments to suit different soil conditions.
Across the D20/D21 series generations, Komatsu refined the undercarriage design and engine efficiency to improve fuel economy and reduce ground pressure. The DDM020-5M-21 matters in the used and parts market because its compact size allows it to fit through standard gate openings and be transported on light trailers, making it highly sought after for residential and municipal projects. Its simple mechanical architecture and widespread availability of aftermarket undercarriage components ensure long-term serviceability and lower total cost of ownership compared to larger, more complex dozers.
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 DDM020-5M-21(S/N 60001-UP (D21PG-6)) specifications
Engine
| Model | Komatsu 4D94E |
| Model (Alternative) | Komatsu 4D94LE-2 |
| Power (Net) | 29.5 kW (40 HP) @ 2,450 rpm |
Weights
| Operating Weight | 8,000–9,000 lb |
Dimensions
| 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 |
| Shoe Width | 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 Speeds | 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 Capacity | Not documented for this exact serial range — verify with your dealer |
Service Capacities
| Hydraulic Tank | 21 L |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
Komatsu DDM020-5M-21(S/N 60001-UP (D21PG-6)) maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
Servicing the DDM020-5M-21(S/N 60001-UP (D21PG-6)) beyond the schedule
Predictive Maintenance & Fluid Analysis
Utilize KOWA oil analysis at every 500-hour interval to monitor wear metals in the engine, hydraulic system, and final drives. Check coolant SCA concentration at 500 hours to prevent scaling and corrosion in the DDM020-5M-21's cooling passages. Monitor hydraulic oil particle count to detect pump or valve wear early. Track fuel consumption trends to identify injector issues before they cause power loss. Use KOMTRAX telematics to log fault codes and hour accumulation for accurate interval scheduling.
Corrective & Common Repairs
Address track tension issues promptly by adjusting the track adjuster via the grease zerk to prevent excessive wear on sprockets and idlers. Replace hydraulic return filters at 500 hours to protect sensitive control valves from contamination. Inspect and torque blade mounting bolts and end bits regularly to maintain cutting edge integrity. Check hydraulic hose conditions for cracks or leaks, especially near the boom and stick cylinders. Replace worn track shoes or pads to maintain proper ground pressure and traction.
Overhaul & Rebuild Points
Plan for final drive oil changes at 1,000 hours to prevent gear wear and seal failure. Inspect the turbocharger at 1,000 hours for shaft play or oil leaks. Evaluate undercarriage components (rollers, idlers, sprockets) for wear at 2,000 hours to determine if replacement is needed. Check the transmission and torque converter for slippage or overheating signs. Inspect the engine air filter element and clean or replace as needed to maintain proper airflow and engine performance.
Seasonal & Environment Servicing
In cold weather, ensure the coolant mixture is rated for the lowest expected temperature to prevent freezing. Use the correct viscosity engine oil (SAE 10W or 30) based on ambient conditions to ensure proper lubrication at startup. In dusty environments, check the air filter restriction indicator more frequently and clean the radiator and oil cooler fins daily to prevent overheating. In wet or muddy conditions, inspect the undercarriage for mud buildup that can accelerate wear and increase rolling resistance.
DDM020-5M-21(S/N 60001-UP (D21PG-6)) common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 103-60-23240 | Cartridge,Hydraulic Oil Filter | Hydraulic service | Check fitment → |
| 113-60-43320 | Cartridge,Hydraulic Oil Filter (D31s) | Hydraulic service | Check fitment → |
| 113-60-43321 | Cartridge,Hydraulic Oil Filter (D31s) | Hydraulic service | Check fitment → |
| 08036-01414 | Clip,(For Add.Filter)(Except Japan) | Scheduled service item | 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.
DDM020-5M-21(S/N 60001-UP (D21PG-6)) fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| CA115 | Engine crankshaft speed sensor failure | Faulty speed sensor, broken wiring harness, or corroded connector at the pin interface. | Replace the speed sensor and verify voltage at the pin connector. |
| CA111 | Internal engine controller fault | Electronic Control Module (ECM) internal failure. | Replace or reprogram the ECM. |
| CA441 | Battery voltage too low | Weak battery, failing alternator, or loose connections. | Replace the battery or alternator; check the voltage regulator. |
| CA442 | Battery voltage too high | Alternator overcharging or voltage regulator failure. | Replace the alternator or battery; check the voltage regulator. |
| CA122 | Intake air pressure sensor feedback voltage too high | Sensor malfunction or wiring short. | Verify the intake pressure sensor and wiring. |
| CA123 | Intake air pressure sensor feedback voltage too low | Sensor short or airflow restriction. | Check for a sensor short or an airflow restriction. |
| CA153 | Intake air temperature sensor feedback voltage too high | Faulty Intake Air Temperature (IAT) sensor. | Replace or test the IAT sensor. |
| CA154 | Intake air temperature sensor feedback voltage too low | Faulty Intake Air Temperature (IAT) sensor. | Replace or test the IAT sensor. |
| 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. |
| CA452 | Common rail pressure sensor feedback value too low | Fuel rail pressure sensor failure or leak. | Diagnose the fuel rail pressure sensor or pump lines. |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
DDM020-5M-21(S/N 60001-UP (D21PG-6)) attachments & work tools
Blades
The DDM020-5M-21 (D21PG-6) is a compact dozer in the D20/D21 small dozer line, which features smaller blade capacities suitable for grading, leveling, and pushing light materials. Typical widths and capacities for this class are not explicitly documented in the provided sources, but the machine is designed for light-duty tasks with lower operating weights.
Rippers
Specific ripper options (multi-shank vs. single-shank) and weights for the DDM020-5M-21 are not detailed in the provided sources. The D20/D21 line is described as a light substantial dozer with operating weights ranging from 8,000 to 9,000 lbs depending on options, which limits the size and weight of compatible rear attachments.
Winches
Winch options for the DDM020-5M-21 are not specified in the provided sources. The machine is noted for its light weight and ability to be hauled on a 12,000 GVW trailer, suggesting it is not typically equipped with heavy-duty towing winches common on larger dozers.
Drawbars/Counterweights
Drawbar and counterweight specifications for the DDM020-5M-21 are not provided in the sources. The D20/D21 series is characterized by lighter operating weights (8,000-9,000 lbs) and is designed for light construction and landscaping rather than heavy pulling or grading tasks requiring large counterweights.
Cab/ROPS Guarding
Forestry or waste configuration guarding options for the DDM020-5M-21 are not documented in the provided sources. The machine is described as a compact dozer with a comfortable operator environment, but specific protective guarding for specialized industries is not listed.
Hydraulic Arrangement
The DDM020-5M-21 uses Komatsu 10W hydraulic oil in its hydraulic tank, as noted in operator discussions for the D21 series. The hydraulic system does not use regular hydraulic fluid, and specific front/rear tool arrangement details are not provided in the sources.
All DDM020-5M-21(S/N 60001-UP (D21PG-6)) assemblies by section
Every catalogued assembly group for the Komatsu DDM020-5M-21(S/N 60001-UP (D21PG-6)). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Control System
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Control System : Oil Cooler Piping (For Trimming Dozer)
| 01***16 | Bolt, Battery To Frame Ground Wire Attaching | 2 |
| 01***30 | Bolt,(For Quick Shift) (Mitsubishi) | 4 |
| 01***45 | Bolt,(For Power Tilt Mech Angle) | 2 |
Engine Related Parts And Electrical System
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Engine Related Parts And Electrical System : Back-Up Alarm (For Trimming Dozer)
| 01***16 | Bolt (Welded) | 1 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 4 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 1 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Engine Related Parts And Electrical System : Electrical System (For Trimming Dozer)
| 01***16 | Bolt (With Air Heater & Conditioner) | 2 |
| 01***20 | Bolt,(With Auto Emergency Steering) | 1 |
| 01***16 | Bolt, Battery To Frame Ground Wire Attaching | 10 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Engine Related Parts And Electrical System : Instrument Panel (For Trimming Dozer)
| 01***12 | Bolt, Bolt,(No Need To Quick Shift) | 1 |
| 01***16 | Bolt, Mount Washer Tank To Bracket, Bolt | 2 |
| 01***16 | Bolt, Battery To Frame Ground Wire Attaching | 4 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Engine Related Parts And Electrical System : Radiator And Piping (For Trimming Dozer)
| 01***16 | Bolt (With Air Heater & Conditioner) | 4 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 7 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 3 |
Guard
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Guard : Cross Bar (For Trimming Dozer)
| 01***40 | Bolt,R.H. Outside And L.H. Inside, Bolt | 8 |
| 01***60 | Bolt,(For Ripper) | 16 |
| 01***45 | Bolt | 8 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Guard : Loader Frame And Floor Plate (For Trimming Dozer) (With Rops Cab)
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 12 |
| 01***30 | Bolt,(For Quick Shift) (Mitsubishi) | 2 |
| 01***55 | Bolt,(For Reinforced Type) | 12 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Guard : Radiator Guard And Hood (For Trimming Dozer)
| 01***30 | Bolt,(For Center Guard) | 2 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 4 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 11 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Guard : Rear Cover And Hydraulic Tank (For Trimming Dozer)(#60001-64227)
| 01***20 | Bolt,(With Auto Emergency Steering) | 3 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 8 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 6 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Guard : Rear Cover And Hydraulic Tank (For Trimming Dozer)(#64228-)
| 01***20 | Bolt,(With Auto Emergency Steering) | 3 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 8 |
| 01***40 | Bolt,(With Service Valve R.H.) | 4 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Guard : Rear Guard (For Trimming Dozer)
| 01***65 | Bolt,L.H | 10 |
| 01***45 | Washer,(Without R.O.P.S.) | 10 |
| 10***10 | Guard,Rear | 1 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Guard : Under Guard (For Trimming Dozer)
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 3 |
| 01***30 | Bolt-Hex, Bolt,(With Center Guard) | 12 |
| 01***30 | Washer, Spring (Supplied W/Spider Assembly), Washer-Spring | 3 |
Main Clutch?Transmission? Steering And Final Drive
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Main Clutch?Transmission? Steering And Final Drive : Final Drive Gear (For Trimming Dozer)
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 16 |
| 01***25 | Bolt,(Without Rops Guard? Canopy) | 4 |
| 01***30 | Washer, Spring (Supplied W/Spider Assembly), Washer-Spring | 16 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Main Clutch?Transmission? Steering And Final Drive : Steering Case And Main Frame (For Trimming Dozer)
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 6 |
| 01***45 | Bolt,(For Power Tilt Mech Angle) | 11 |
| 01***30 | Washer, Spring (Supplied W/Spider Assembly), Washer-Spring | 11 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Main Clutch?Transmission? Steering And Final Drive : Steering Clutch (For Trimming Dozer)
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 16 |
| 01***10 | Nut (K10) | 2 |
| 01***30 | Washer, Spring (Supplied W/Spider Assembly), Washer-Spring | 16 |
Track
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Track : Track Shoe (Rubber Type) (For Trimming Dozer)
| 10***70 | Shoe,Rubber | 2 |
Work Equipment
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Work Equipment : Hydraulic Piping (Tilt Cylinder Line) (Dozer Side) (For Trimming Dozer)
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 18 |
| 01***30 | Washer, Spring (Supplied W/Spider Assembly), Washer-Spring | 18 |
| 01***32 | Washer,(With Auto Emergency Steering) | 16 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Work Equipment : Trimming Cylinder
| 07***70 | O-Ring,(For Intake Air Cover) | 1 |
| 07***65 | O-Ring,(F5350-62a0 -14 ) | 1 |
| 07***65 | Ring,Back-Up (Kit) | 1 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Work Equipment : Trimming Dozer Blade
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 10 |
| 01***30 | Washer, Spring (Supplied W/Spider Assembly), Washer-Spring | 10 |
| 07***00 | Fitting, Grease - Upper Hinge Pin | 4 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Work Equipment : Trimming Dozer Frame
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 4 |
| 01***85 | Bolt,(For 2nd Travel Speed) (Op) | 2 |
| 01***50 | Bolt,(For Tbg/Abe Spec.) | 24 |
Work Equipment Control System
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Work Equipment Control System : Control Valve (For Trimming Dozer) (1/2)
| 01***16 | Bolt (Op) | 4 |
| 01***25 | Bolt, Seal Cover Mounting | 2 |
| 01***30 | Bolt | 2 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Work Equipment Control System : Control Valve (For Trimming Dozer) (2/2)
| 01***08 | Nut (Op) | 1 |
| 07***11 | O-Ring (Kit) | 1 |
| 07***14 | O-Ring,(F4350-61a0a-20 ) | 2 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Work Equipment Control System : Hydraulic Piping (Lift Cylinder Line) (For Trimming Dozer)
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 4 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 4 |
| 01***30 | Bolt,(For Quick Shift) (Mitsubishi) | 6 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Work Equipment Control System : Hydraulic Piping (Tank To Pump To Valve) (For Trimming Dozer)
| 01***45 | Screw | 4 |
| 01***16 | Bolt, Battery To Frame Ground Wire Attaching | 1 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 1 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Work Equipment Control System : Hydraulic Piping (Tilt Cylinder Line) (Chassis Side) (For Trimming Dozer)
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 2 |
| 01***30 | Bolt,(For Quick Shift) (Mitsubishi) | 8 |
| 01***35 | Bolt,(For Quick Shift) (Mitsubishi) | 4 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Work Equipment Control System : Hydraulic Tank And Filter (For Trimming Dozer )
| 01***25 | Bolt,Without Revolution Sensor | 7 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 3 |
| 01***30 | Bolt? Wing,Inspection Cover | 1 |
Komatsu : Ddm020-5m-21(S/N 60001-Up (D21pg-6)) : Work Equipment Control System : Lift Cylinder (For Trimming Dozer)
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 1 |
| 01***09 | Nut,(With Body Positioner) | 2 |
| 01***23 | Washer, Wiring Harness Mounting Bracket | 2 |
Frequently asked questions
What engine does the Komatsu DDM020-5M-21 use?
The Komatsu DDM020-5M-21 is equipped with a Komatsu 4D94E diesel engine, producing approximately 29.5 kW (40 HP) at 2,450 rpm.
What is the operating weight of the Komatsu DDM020-5M-21?
The operating weight of the Komatsu DDM020-5M-21 ranges from approximately 8,000 to 9,000 lbs (3,629 to 4,082 kg), depending on the specific configuration and attached equipment.
What model replaced the Komatsu DDM020-5M-21?
The Komatsu DDM020-5M-21 is part of the D20/D21 series lineage. It was succeeded by newer generations such as the D21PG-6, which features updated emissions compliance and improved efficiency.
What DDM020-5M-21(S/N 60001-UP (D21PG-6)) owners discuss
What engine is installed in the Komatsu DDM020-5M-21 (S/N 60001-UP, D21PG-6)?
What are the common hydraulic fluid and lubricant specifications for this dozer?
What are the typical undercarriage and wear patterns for this machine type?
What are the known engine quirks and powertrain behaviors for the D21 series?
What are the common electrical and sensor issues reported by owners?
What is a critical steering issue specific to the Dash 5 series of this dozer?
What should be checked when buying a used DDM020-5M-21 (S/N 60001-UP, D21PG-6)?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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