Komatsu DDM020_5K_AC(S/N 60001-UP (D20A-6))
Maintenance schedule, common problems & OEM parts breakdown
The Komatsu DDM020_5K_AC (S/N 60001-UP, D20A-6) is a compact crawler dozer built for small-site grading and utility work. It runs the naturally aspirated Komatsu 4D95S / 4D95S-W-1 diesel, a 2.7-liter 4-cylinder mechanical engine rated around 40 hp (29.8 to 29.9 kW) at 2450 rpm, with no electronic engine controls. Operating weight is roughly 3,550 kg (7,826 lb). Drive is direct-drive mechanical with a foot-operated main clutch and a 3-forward/2-reverse gearbox, steered through dry-disc steering clutches and brakes at each final drive. This D20A-6 built generation dates to the mid-1980s through early 1990s, the SN 60001-up range falling under the factory shop manual issued in 1990. It succeeded the earlier D20A-5 and was itself followed by the D20A-7. The same chassis family was offered with a powershift/torque-converter drivetrain as the D21A-6, plus angling-blade and other work-equipment variants across the D20 and D21 lines.
Across this dozer's series history the core layout stayed simple and mechanical: the -5 predecessor carried an earlier engine tune, the -6 generation covered here standardized the 4D95S engine and shop-manual documentation under SN 60001-up, and the -7 successor brought engine updates plus a joystick steering option, with single-lever blade control added on later units. The parallel D21A-6 swapped the foot-clutch drivetrain for a torque-converter powershift, trading some fuel economy for smoother direction changes, while the D20A kept the cheaper, simpler mechanical clutch-and-brake setup that owners of this class still prize for field repairability. In today's used and parts market this dozer holds value precisely because it has no ECM or hydrostatic drive to fail: aftermarket support centers on 4D95S engine rebuild kits (shared with period Komatsu excavators), undercarriage wear parts, and mechanical clutch and steering components, making it a workable low-cost option for landscaping, small-site earthmoving, and confined-space grading where a full-size dozer does not fit.
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_5K_AC(S/N 60001-UP (D20A-6)) specifications
Engine
| Model | Komatsu 4D95S (4D95S-W-1), naturally aspirated 4-cylinder diesel |
| Gross power | 29.8-29.9 kW (40 hp) at 2450 rpm |
| Displacement | 2.7 L (164.2 cu in) |
| Cylinders | 4, in-line, water-cooled |
| Emissions tier | Pre-emissions era (1985-1992 production run); no EPA/EU tier certification published |
Weights
| Operating weight, standard | 3,550 kg (7,826 lb) with standard blade |
| Note on configuration | Figure is for the narrow-gauge "A" (angle/straight) blade dozer with standard single-grouser shoes; wider-shoe or swamp configurations documented under the related D20P designation are not carried over here |
Dimensions
| Overall length with blade | 3,400 mm (11 ft 2 in) |
| Length without blade | 2,550 mm (8 ft 4 in) |
| Overall width over tracks | 1,610 mm (5 ft 4 in) |
| Height to top of cab/canopy | 2,475 mm (8 ft 2 in) |
| Ground clearance | 295 mm (11.6 in) |
| Track gauge (centerline to centerline) | 1,310 mm (4 ft 4 in) |
| Track length on ground | 1,685 mm (5 ft 6 in) |
| Track pitch | 135 mm (5.3 in) |
| Standard shoe width | 300 mm (11.8 in) single-grouser; wider swamp/pyramid shoes were available on other D20 variants but not confirmed for this configuration |
| Track rollers per side | 5 carrier/track rollers per side |
Performance
| Transmission | Direct-drive (DD) mechanical transmission, foot clutch with floor-mounted shift lever; 3 forward and 2 reverse speeds. |
| Travel speed | Not documented with confirmed forward/reverse km/h figures for this exact serial range across available sources; general references describe the 3rd forward gear as the fastest, suited to overland travel. Verify exact gear speeds with your dealer or the factory operation manual |
| Ground pressure | Not documented as a factory-published figure for the stock 300 mm shoe configuration in accessible sources; owners report ground pressure decreases with wider aftermarket shoe options, implying the stock narrow-shoe figure runs higher than roughly 4.5-5 psi. Treat as unconfirmed and verify with dealer |
| Drawbar pull / gradeability | Not documented for this model/serial range in the sources checked |
Blades
| Blade type | Straight/angle dozer blade (standard configuration for this narrow-track A-series machine) |
| Blade width | 2,170 mm (7 ft 2 in) |
| Blade height | 590 mm (23.3 in) |
| Blade capacity | Not documented as a struck/heaped capacity figure in accessible sources for this configuration |
Service capacities summary
| Fuel tank | Approximately 60-62 L (15.8-16.4 US gal); figure varies slightly by source, treat as approximate |
| Engine oil | Not documented for this exact model in accessible sources; consult the factory operation and maintenance manual |
| Cooling system | Not confirmed for this exact model; the closely related predecessor D20A-5 lists roughly 13 L (3.4 gal), offered only as a reference point, not a confirmed figure for this D20A-6 configuration |
| Hydraulic system | Not documented for this exact model in accessible sources; consult the factory operation and maintenance manual |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
DDM020_5K_AC(S/N 60001-UP (D20A-6)) fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with filter) | Not published in any source we could access for this exact S/N 60001-up range. Based on the 4D95S-W-1 engine shared across the D20/D21-6 through -8 chassis generations, refill runs roughly 6.5 to 7.0 L (6.9 to 7.4 US qt) with filter change. Treat as an approximation and confirm against the OMM or dealer before service. | Komatsu-spec diesel engine oil (API CD/CF class equivalent), graded by ambient temperature per Komatsu's standard viscosity chart for this era: SAE10W in cold weather (below roughly 0 C / 32 F), SAE30 in the 0 to 35 C range, or an all-season 15W-40 diesel engine oil where year-round temperature swing is wide. |
| Cooling system | Approximately 13 L (3.4 US gal), carried over from the D20A-5/D21A-5 predecessor sharing the same 4D95S engine and chassis. Not confirmed as the exact factory figure printed in the D20A-6/D21A-6 (S/N 60001-up) OMM; a later D21A-8 generation lists a smaller 10 L system, so verify before topping off. | Komatsu Supercoolant or an equivalent low-silicate ethylene-glycol antifreeze/corrosion-inhibitor coolant, mixed to the freeze-protection ratio called out in the OMM's cold-weather chart for the operating region. |
| Fuel tank | Approximately 60 L (15.9 US gal). This is well corroborated across the surrounding generations: the D20A-5 predecessor lists 60.18 L (15.90 gal) and the D20A-7 successor family lists 59.95 L (15.84 gal), both sharing this tank design, so the D20A-6 figure should sit in the same range. | No. 2-D diesel fuel for normal conditions; switch to No. 1-D or a winter-blend diesel below about 0 C (32 F) to avoid fuel waxing/gelling, per Komatsu's standard cold-weather operating guidance. |
| Powershift transmission | Not documented for this exact serial range in the sources available online. Verify with the OMM or a Komatsu dealer for the exact refill figure. | Komatsu powertrain oil (TO-class), graded by ambient temperature. Komatsu's factory cross-reference for this chassis pairs a lighter-viscosity gear oil for cold climates with a heavier grade for warm climates, consistent with the later TO10 (cold) / TO30 (warm) split used across this dozer family. |
| Bevel gear / steering clutch compartment | Not documented for this exact serial range in the sources available online. | Same Komatsu powertrain (TO-class) gear oil used in the transmission case; factory lubrication guides for this chassis list the bevel gear and steering/transmission compartments as sharing one oil spec, split by climate the same way as the transmission. |
| Final drives (each side) | Not documented for this exact serial range in the sources available online; do not rely on figures found for other Komatsu dozer families (they vary widely by machine class and were not confirmed as applying to the D20A-6). | Komatsu powertrain/gear oil (TO or AXO-class), viscosity graded by ambient temperature the same as the transmission and bevel gear compartments. |
| Hydraulic system/tank | Not documented for this exact serial range in the sources available online. | On this generation of small Komatsu dozer, the hydraulic reservoir typically runs an engine-oil-viscosity-equivalent fluid rather than a dedicated multi-grade hydraulic oil (predecessor to today's Komatsu HO-series hydraulic fluid). Confirm the exact grade against the OMM before refilling. |
| Pivot shaft | Not listed as a separate refill point in any source reviewed for this machine; likely serviced as a grease point rather than an oil-fill compartment. | See grease specification below. |
| Grease points | No refill capacity applies; grease points are serviced by pump strokes at the periodic maintenance interval, not by a fill volume. | Komatsu multipurpose lithium-based grease, NLGI 2 (equivalent to today's Komatsu G2-Li), applied at pivot pins, track idlers/rollers, and work-equipment linkage points per the OMM's periodic maintenance chart. |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Komatsu DDM020_5K_AC(S/N 60001-UP (D20A-6)) maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 50 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 4,000 h |
|
Servicing the DDM020_5K_AC(S/N 60001-UP (D20A-6)) beyond the schedule
Predictive Maintenance & Fluid Analysis
This D20A-6 has no ECM, so condition monitoring relies on oil sampling and visual inspection rather than fault codes. Send engine, transmission, and final drive oil samples in at each 500h to 1000h drain to catch clutch-lining wear or steering-clutch slippage before it becomes a rebuild. Watch coolant color and smell for combustion gas intrusion in the naturally aspirated 4D95S, and track fuel filter sediment volume as an early warning of tank or line contamination on this mechanically injected engine.
Corrective & Common Repairs
Typical failures on this model center on the foot-operated main clutch and dry-disc steering clutches: dragging or slipping steering usually traces to worn friction plates or maladjusted linkage rather than hydraulic faults. Check final drive case oil for metal contamination if steering feels uneven side to side. Fuel injection pump and injector issues on the 4D95S show up as hard starting or smoking, and are corrected with pump timing checks and nozzle service rather than electronic diagnostics.
Overhaul & Rebuild Points
Plan engine overhaul around block, ring, and bearing wear on the 2.7-liter 4D95S once compression drops or oil consumption climbs; this engine shares rebuild kits with period Komatsu excavator applications. Steering clutch and brake packs in the final drives are the other major wear item on this direct-drive machine and should be inspected for plate thickness whenever adjustment no longer holds. Undercarriage rebuild (track links, bushings, rollers) follows normal wear-limit inspection given the machine's light operating weight.
Seasonal & Environment Servicing
Before cold-weather operation, switch to a lower-viscosity engine oil and check coolant freeze protection, since this naturally aspirated diesel has no glow-plug electronics to compensate for cold starts. In dusty or abrasive ground conditions, shorten air cleaner and fuel filter service intervals and inspect the dry-disc steering clutches more often, since grit accelerates plate wear. In wet or muddy sites, grease track and pivot points more frequently and check final drive seals for water intrusion given the low ground clearance of this compact dozer.
DDM020_5K_AC(S/N 60001-UP (D20A-6)) common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 07000-02080 | O-Ring,Hydraulic Oil Filter | Hydraulic service | Check fitment → |
| 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 → |
| 07000-02075 | O-Ring,Steering Oil Filter | Lubrication service | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
DDM020_5K_AC(S/N 60001-UP (D20A-6)) fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| CHARGE lamp (battery/alternator symbol) | Charging circuit not producing current; battery running on stored charge only | Slipping or broken fan belt, faulty alternator, loose or corroded wiring connection | Check fan belt tension and condition first, then inspect alternator wiring and output |
| Engine oil pressure lamp | Engine lubrication pressure below safe threshold | Low engine oil level, worn oil pump, clogged oil filter or strainer | Stop engine immediately, check oil level, inspect filter before restarting |
| Coolant temperature gauge in red/high range | Engine coolant temperature above normal operating range | Low coolant level, clogged radiator fins, slipping fan belt, faulty thermostat | Idle down and let cool, check coolant level and radiator for debris, inspect belt |
| Air cleaner restriction indicator | Intake air filter element is clogged, restricting airflow to engine | Dirty or saturated air filter element from dusty jobsite conditions | Inspect and clean or replace the air filter element |
| Parking brake indicator lamp | Parking brake is engaged | Lever left in applied position, or brake linkage/switch fault keeping lamp lit | Confirm lever position, inspect brake linkage and switch if lamp stays lit with lever released |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
DDM020_5K_AC(S/N 60001-UP (D20A-6)) attachments & work tools
Blades
The D20A-6 is the angling-dozer variant of this family (narrow-track "A" chassis), typically fitted with a straight/angle blade around 2170mm (7.2 ft) wide by 590mm (23.3 in) high; some dealer listings describe a full 6-way PAT (power angle tilt) blade near 2160mm (85 in) wide on this chassis. The wide-track "P" sibling in the same family runs a wider blade near 2540mm (8 ft 4 in), narrowing to about 2440mm (8 ft) when angled — do not apply that width to the D20A-6. No SU (semi-U) blade or VPAT (variable power-angle-tilt) option is documented for this compact class; those show up on larger D-series dozers, not this one.
Rippers
Factory literature located for this exact serial range does not spec a catalog ripper attachment; this is a roughly 3.5 tonne class machine and ripper fitment is uncommon. Owner/field reports describe rear-mounted shank rippers used for shallow scarifying, but shank count and penetration/weight figures are not confirmed in available documentation — treat as varies by configuration and verify with a dealer.
Winches
No OEM winch package is confirmed for the D20A-6 in available sources; the standard rear fitment on this machine is a drawbar, not a winch mount. Small dozers of this era in the Komatsu D20/D21 family could be fitted with aftermarket cable winches, but no specific winch model or capacity ties to this serial range — treat winch fitment as a field conversion, not a factory line option.
Drawbars/counterweights
A rear drawbar is standard equipment on the D20A-6 per dealer/auction listings for this model. No separate factory counterweight package is documented for this class; blade-only configurations on a machine this size do not typically call for added counterweight.
Cab/ROPS guarding for forestry/waste configs
Standard operator protection is a 4-post ROPS/sweeps canopy. No factory forestry or waste-handling guarding package is documented for this compact class at this era; brush/forestry protection on machines like this is typically an aftermarket addition — mesh or expanded-metal screen panels fitted to the rear and sides of the ROPS structure to shield the operator during clearing work.
Hydraulic arrangement (front/rear tools)
Front blade control runs off dedicated lift, tilt, and angle cylinders (PAT-style circuit) fed by the machine's main hydraulic pump. No factory rear hydraulic circuit is documented for this model — the standard rear fitment (drawbar) is mechanical, and any rear-mounted ripper or winch would require an auxiliary circuit tapped into the main system; specific plumbing/valve arrangement for such a conversion is not covered in available literature for this serial range.
All DDM020_5K_AC(S/N 60001-UP (D20A-6)) assemblies by section
Every catalogued assembly group for the Komatsu DDM020_5K_AC(S/N 60001-UP (D20A-6)). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Control System
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Control System : Main Clutch Pedal (For Lever Steering) (For Trimming Dozer)
| 01***30 | Bolt,(For Mechanical Governor) | 1 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 2 |
| 01***30 | Bolt,(For Quick Shift) (Mitsubishi) | 3 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Control System : Oil Cooler Piping (For Trimming Dozer)
| 01***16 | Bolt, Battery To Frame Ground Wire Attaching | 2 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 1 |
| 01***40 | Bolt, Mount Master Brake Cylinder | 2 |
Engine Related Parts And Electrical System
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-6)) : Guard : Loader Frame And Floor Plate (For Trimming Dozer)
| 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_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-6)) : Guard : Rear Cover And Hydraulic Tank (For Trimming Dozer)(#60001-63964)
| 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_5k_ac(S/N 60001-Up (D20a-6)) : Guard : Rear Cover And Hydraulic Tank (For Trimming Dozer)(#63965-)
| 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_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-6)) : Main Clutch?Transmission? Steering And Final Drive : Inertia Brake (For Trimming Dozer)
| 01***20 | Bolt,(With Auto Emergency Steering) | 4 |
| 01***35 | Bolt,(For Quick Shift) (Mitsubishi) | 1 |
| 01***06 | Nut,(With Back-Up Alarm) (Op), Nut; Was 01580-10806 | 5 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Main Clutch?Transmission? Steering And Final Drive : Main Clutch Case (For Trimming Dozer)
| 01***20 | Bolt,(With Auto Emergency Steering) | 4 |
| 01***25 | Bolt,Without Revolution Sensor | 4 |
| 01***30 | Bolt,(For Mechanical Governor) | 4 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Main Clutch?Transmission? Steering And Final Drive : Main Clutch Plate (For Trimming Dozer)
| 01***10 | Bolt, Mount Flasher | 6 |
| 01***45 | Bolt,(For Suction? Reversible Fan) | 3 |
| 01***16 | Bolt, Mount Washer Tank To Bracket, Bolt | 6 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Main Clutch?Transmission? Steering And Final Drive : Main Clutch Yoke (For Trimming Dozer)
| 01***30 | Bolt,(For France Noise Suppression) | 2 |
| 01***35 | Bolt,(For Quick Shift) (Mitsubishi) | 1 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 2 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-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 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Main Clutch?Transmission? Steering And Final Drive : Transmission (1/5) (Case) (For Trimming Dozer)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***30 | Bolt,(For France Noise Suppression) | 8 |
| 01***40 | Bolt,(Dust And Dirt Protection) | 2 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Main Clutch?Transmission? Steering And Final Drive : Transmission (2/5) (Main Shaft And Gear) (For Trimming Dozer)
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 3 |
| 01***10 | Nut | 1 |
| 01***30 | Washer, Spring (Supplied W/Spider Assembly), Washer-Spring | 3 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Main Clutch?Transmission? Steering And Final Drive : Transmission (3/5) (Intermediate Shaft And Gear) (For Trimming Dozer)
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 3 |
| 01***30 | Washer, Spring (Supplied W/Spider Assembly), Washer-Spring | 3 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Main Clutch?Transmission? Steering And Final Drive : Transmission (4/5) (Counter Shaft And Gear) (For Trimming Dozer)
| 01***16 | Bolt,(For Slag Handling) | 2 |
| 01***40 | Bolt, Mount Master Brake Cylinder | 3 |
| 01***30 | Washer, Spring (Supplied W/Spider Assembly), Washer-Spring | 3 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Main Clutch?Transmission? Steering And Final Drive : Transmission (5/5) (Shift Lever And Fork) (For Trimming Dozer)
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 4 |
| 01***12 | Screw,(With Articulate Indicator) | 4 |
| 01***20 | Screw,Set | 3 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Main Clutch?Transmission? Steering And Final Drive : Universal Joint (For Trimming Dozer)
| 01***40 | Bolt,(With Air Conditioner) | 8 |
| 01***25 | Washer,Spring?For Additional Rear Lam | 8 |
| 07***75 | Fitting,Grease (Without Lub. Piping) | 1 |
Track
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Track : Recoil Spring (For Trimming Dozer)
| 01***16 | Bolt (With Air Heater & Conditioner) | 10 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 4 |
| 01***30 | Bolt,(Not Used With Emergency Str.) | 8 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Track : Track Frame (For Trimming Dozer)
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 12 |
| 01***25 | Bolt,(For Rubber Shoe) | 24 |
| 01***35 | Bolt,R.H. Outside And L.H. Inside | 16 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Track : Track Roller (For Trimming Dozer)
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 12 |
| 01***45 | Bolt, Mount Center Hinge Retainer (Upper) | 48 |
| 01***25 | Washer,Spring?(Sandy And Dusty Spec.) | 12 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Track : Track Shoe (Lubricate Type) (Single Grouser With Hole)
| 01***18 | Nut? Shoe (Kit) | 642 |
| 07***22 | Plug,Large | 152 |
| 07***21 | Plug,(Small) | 152 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Track : Track Shoe (Master Pin Type) (Semi-Double Grouser With Hole)
| 01***18 | Nut? Shoe (Kit) | 362 |
| 10***21 | Link,Track? L.H | 78 |
| 10***31 | Link,Track? R.H | 78 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Track : Track Shoe (Master Pin Type) (Single Grouser With Hole)
| 01***18 | Nut? Shoe (Kit) | 658 |
| 10***06 | Track Shoe Ass'Y | 1 |
| 10***07 | Track Shoe Ass'Y | 1 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Track : Track Shoe (Master Pin Type) (Single Grouser)
| 01***18 | Nut? Shoe (Kit) | 658 |
| 10***07 | Track Shoe Ass'Y | 1 |
| 10***08 | Track Shoe Ass'Y | 1 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Track : Track Shoe (Master Pin Type) (Triple Grouser With Hole)
| 01***18 | Nut? Shoe (Kit) | 658 |
| 10***20 | Link,Track? L.H | 74 |
| 10***21 | Link,Track? L.H | 152 |
Work Equipment
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-6)) : Work Equipment Control System : Control Valve (1/2) (For Trimming Dozer)
| 01***16 | Bolt (Op) | 4 |
| 01***25 | Bolt, Seal Cover Mounting | 2 |
| 01***30 | Bolt | 2 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Work Equipment Control System : Control Valve (2/2) (For Trimming Dozer)
| 01***08 | Nut (Op) | 1 |
| 07***11 | O-Ring (Kit) | 1 |
| 07***14 | O-Ring,(F4350-61a0a-20 ) | 2 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-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_5k_ac(S/N 60001-Up (D20a-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 |
Komatsu : Ddm020_5k_ac(S/N 60001-Up (D20a-6)) : Work Equipment Control System : Work Equipment Control Lever (For Trimming Dozer)
| 01***16 | Bolt (With Air Heater & Conditioner) | 2 |
| 01***20 | Bolt,(With Auto Emergency Steering) | 8 |
| 01***30 | Bolt,(For Mechanical Governor) | 1 |
Frequently asked questions
What engine powers the Komatsu DDM020_5K_AC (S/N 60001-UP, D20A-6)?
It uses the Komatsu 4D95S / 4D95S-W-1, a naturally aspirated 2.7-liter 4-cylinder diesel producing about 40 hp (29.8 to 29.9 kW) at 2450 rpm, with a fully mechanical fuel system and no electronic engine controls.
What is the operating weight of the Komatsu DDM020_5K_AC (S/N 60001-UP, D20A-6)?
Operating weight is approximately 3,550 kg (7,826 lb), reflecting this dozer's compact class and direct-drive mechanical driveline.
What replaced the Komatsu DDM020_5K_AC (S/N 60001-UP, D20A-6)?
It was succeeded by the D20A-7, which carried engine updates and added a joystick steering option, with single-lever blade control introduced on later production.
What DDM020_5K_AC(S/N 60001-UP (D20A-6)) owners discuss
How does the D20A-6's hydraulic system behave compared to the D21 version of this dozer?
What's the typical behavior and upkeep of the dry-disc steering clutch and brake?
What engine quirks are typical of the 4D95S in this dozer?
What undercarriage wear pattern should owners watch for on the D20A-6?
Are there notable electrical or sensor issues on this dozer?
One track won't respond to the steering lever — what's usually behind it?
What should I check before buying a used D20A-6?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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