Komatsubulldozersmall ( - d39)
Komatsu D20Q-5(S/N 45368-UP)
Maintenance schedule, common problems & OEM parts breakdown
The Komatsu D20Q-5 (S/N 45368-UP) is a compact crawler loader/bulldozer class machine designed for utility and light earthmoving applications. Produced between 1971 and 1988, this unit features the Komatsu 4D94 engine providing 39 hp (29 kW) of net power. The machine operates within an approximate weight range of 8,995 lb (4,080 kg). It is part of the D-series lineage and is often configured with a 0.6 yd³ (0.4 m³) heaped bucket capacity.
Across its production generations, the D20Q-5 maintained a focus on high maneuverability in tight jobsite environments. While later series introduced different emissions tiers and telematics like Komtrax, this specific era relies on mechanical robustness. In today's used market, the D20Q-5 remains significant due to its availability of core components and its utility in small-scale excavation where larger dozers cannot operate. Its simple 4D94 powertrain makes it a preferred choice for parts interchangeability with related D20 series models.
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 D20Q-5(S/N 45368-UP) specifications
Engine
| Engine Model | Komatsu 4D94 |
| Net Power | 39 hp (29.1 kW) |
| Displacement | 179 cu in (3 L) |
| Engine Speed at Max Torque | 2,450 rpm |
Weights
| Operating Weight | 8,994.9 lb (4,080 kg) |
Dimensions
| Transport Length | 11.31 ft in (3,445 mm) |
| Transport Width | 6.57 ft in (2,000 mm) |
| Transport Height | 7.17 ft in (2,185 mm) |
| Ground Clearance | 1.24 ft in (375 mm) |
| Track Width | 58.67 in (1,490 mm) |
| Track Shoe Width | 20.08 in (510 mm) |
Performance
| Max Speed | 4.6 mph (7.4 km/h) |
| Ground Pressure | 3.41 psi (23.52 kPa) |
| Breakout Force - Std Bucket | 8,950 lb (39.9 kN) |
| Static Tipping Load | 5,160 lb (2,340.6 kg) |
Blades/Buckets
| Bucket Capacity - Heaped | 0.6 yd³ (0.4 m³) |
Service Capacities
| Fuel Capacity | 15.9 gal (60 L) |
| Cooling System Fluid Capacity | 3.5 gal (13 L) |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
D20Q-5(S/N 45368-UP) fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine Crankcase (w/ filter) | not documented for this exact serial range — verify with your dealer | Komatsu genuine diesel engine oil |
| Cooling System | not documented for this exact serial range — verify with your dealer | Komatsu super coolant |
| Fuel Tank | not documented for this exact serial range — verify with your dealer | per the operation and maintenance manual |
| Transmission/Powertrain (Powershift Transmission) | not documented for this exact serial range — verify with your dealer | Komatsu powertrain oil |
| Transmission/Powertrain (Bevel Gear/Steering Compartments) | not documented for this exact serial range — verify with your dealer | Komatsu axle oil |
| Final Drives (each) | not documented for this exact serial range — verify with your dealer | per the operation and maintenance manual |
| Hydraulic System/Tank | not documented for this exact serial range — verify with your dealer | Komatsu hydraulic oil |
| Grease | not documented for this exact serial range — verify with your dealer | per the operation and maintenance manual |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Komatsu D20Q-5(S/N 45368-UP) maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
Servicing the D20Q-5(S/N 45368-UP) beyond the schedule
Predictive Maintenance & Fluid Analysis
Monitor the Komatsu 4D94 engine using regular oil sampling to detect internal wear. Regularly check hydraulic fluid clarity and levels to prevent pump cavitation. Use Komatsu genuine lubricants, specifically focusing on maintaining correct levels in the cooling system (approx. 13 L / 3.5 gal) and fuel tank (approx. 60 L / 15.9 gal). Analyzing transmission oil for metal particulates can predict gear failure before it occurs.
Corrective & Common Repairs
Address steering clutch or main clutch intermittent engagement by inspecting hydraulic pressure and seal integrity. If the machine loses steering ability after operating for short durations, check for overheating in the pump or hydraulic circuit. Monitor for CAN communication errors (e.g., DAFRMC) which may indicate sensor or wiring harness faults between the engine and pump controllers. Ensure all electrical connections are free of corrosion.
Overhaul & Rebuild Points
Plan major overhauls around the 2,000-hour milestone, focusing on the 4D94 engine displacement components and fuel system. Inspect the final drive and transmission for significant backlash or wear. During undercarriage rebuilds, evaluate all five track rollers per side and the condition of the 510 mm (20.08 in) track shoes. Rebuilding the hydraulic pump is necessary if breakout force drops below factory specifications.
Seasonal & Environment Servicing
In high-dust environments, increase frequency of air cleaner inspections to prevent engine choking. During cold weather operations, ensure the cooling system is treated with appropriate Komatsu coolant to prevent freezing. For summer use, verify radiator airflow and clean debris from the cooling fins to maintain the 13 L (3.5 gal) capacity without overheating. Check track tension adjustments if operating in muddy or soft soil conditions.
D20Q-5(S/N 45368-UP) common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 07281-00197 | Clamp,(With Pre-Fuel Filter) | Fuel system service | Check fitment → |
| 09019-08035 | Wrench,Filter (For Add. Fuel Filter) | Fuel system service | Check fitment → |
| 08036-01414 | Clip,(For Add.Filter)(Except Japan) | Scheduled service item | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
D20Q-5(S/N 45368-UP) fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| CA428 | Water detected in fuel | Contaminated fuel or saturated water separator element | Stop machine and drain the water separator immediately |
| DAFRMC | CAN communication disconnection (Monitor detected) | Communication error in CAN circuit between pump controller and engine controller; possible wiring harness disconnection, ground fault, or hot short | Inspect wiring harness for disconnections or shorts; system may reset itself if cause disappears |
| E15 | Engine controller serious error | Fault within the engine control unit/controller | Diagnose and repair via qualified technician; engine may have reduced power or fail to start |
| E03 | Parking brake or swing brake system fault | Electrical or mechanical failure in the braking circuit | Inspect brake system components and electrical connections |
| L03 | Swing brake or travel alarm circuit fault | Electrical fault in the specific circuit | Investigate electrical continuity in swing brake/travel alarm wiring |
| L04 | Travel alarm system specific fault | Specific failure within the travel alarm circuit | Inspect travel alarm components and wiring |
| L01 | General low-priority system abnormality | Minor system irregularity | Monitor machine performance for further issues |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
D20Q-5(S/N 45368-UP) attachments & work tools
Blades
Configuration options for S, SU, and A types are not explicitly detailed for this serial range. Blade capacity is noted at approximately 0.52 CY (0.40 m³).
Rippers
Rear ripper availability is not documented for this exact serial range — verify with your dealer.
Drawbars/Counterweights
Specific drawbar or counterweight specifications for this model are not provided in the available documentation.
Cab/ROPS Guarding
The machine lacks factory-specified forestry or waste guarding options in the technical data. One reference notes a 10' 6 Way Blade configuration with EROPS Cab, Heat and A/C for a D20Q-5 unit.
Hydraulic Arrangement
The machine lacks a diesel particulate filter or specific hydraulic arrangement notes for front/rear tools. Standard Komatsu lubricants include AXO, HO, and EO fluids.
All D20Q-5(S/N 45368-UP) assemblies by section
Every catalogued assembly group for the Komatsu D20Q-5(S/N 45368-UP). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Engine Related Parts And Electrical System
Komatsu : D20q-5(S/N 45368-Up) : Engine Related Parts And Electrical System : Air Cleaner Connection(#51538-)
| 07***09 | Clamp,(See Fig. K0210-16a0) | 2 |
| 10***60 | Boot | 1 |
| 10***70 | Pipe | 1 |
Komatsu : D20q-5(S/N 45368-Up) : Engine Related Parts And Electrical System : Battery
| 01***30 | Bolt,(Cold Terrain Spec.) | 4 |
| 01***18 | Bolt | 4 |
| 01***06 | Nut, Regular Hexagon (M8-1.25) | 8 |
Komatsu : D20q-5(S/N 45368-Up) : Engine Related Parts And Electrical System : Electrical System
| 01***12 | Bolt (M8-1.25x12) | 2 |
| 01***16 | Bolt,(Sandy And Dusty Spec.) | 13 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 1 |
Komatsu : D20q-5(S/N 45368-Up) : Engine Related Parts And Electrical System : Engine Mounting Parts(#45368-51537)
| 01***10 | Bolt | 4 |
| 10***20 | Cushion,Rear | 8 |
| 11***20 | Washer | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Engine Related Parts And Electrical System : Engine Mounting Parts(#51538-)
| 01***10 | Bolt | 4 |
| 10***20 | Cushion,Rear | 4 |
| 10***30 | Cushion,Front | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Engine Related Parts And Electrical System : Fuel Control Lever
| 01***20 | Bolt,(Large Capacity Type) (Std) | 10 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 1 |
| 01***16 | Screw | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Engine Related Parts And Electrical System : Fuel Tank And Piping
| 01***16 | Bolt,(Sandy And Dusty Spec.) | 3 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 3 |
| 07***20 | Cap Ass'Y | 1 |
Komatsu : D20q-5(S/N 45368-Up) : Engine Related Parts And Electrical System : Fuel Tank? Additional Strainer And Piping(#45368-50865)
| 01***16 | Bolt,(Sandy And Dusty Spec.) | 3 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 1 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 1 |
Komatsu : D20q-5(S/N 45368-Up) : Engine Related Parts And Electrical System : Fuel Tank? Additional Strainer And Piping(#50866-)
| 01***16 | Bolt,(Sandy And Dusty Spec.) | 3 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 1 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 3 |
Komatsu : D20q-5(S/N 45368-Up) : Engine Related Parts And Electrical System : Instrument Panel(#45368-51599)
| 01***16 | Bolt,(Sandy And Dusty Spec.) | 2 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 3 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 3 |
Komatsu : D20q-5(S/N 45368-Up) : Engine Related Parts And Electrical System : Instrument Panel(#51600-)
| 01***16 | Bolt,(Sandy And Dusty Spec.) | 1 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 3 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 3 |
Komatsu : D20q-5(S/N 45368-Up) : Engine Related Parts And Electrical System : Oil Cooler And Piping
| 01***20 | Bolt,(Large Capacity Type) (Std) | 3 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 2 |
| 01***40 | Bolt,(Dust And Dirt Protection) | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Engine Related Parts And Electrical System : Radiator And Piping(#45368-51537)
| 01***12 | Bolt (M8-1.25x12) | 3 |
| 01***16 | Bolt,(For Slag Handling) | 4 |
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Engine Related Parts And Electrical System : Radiator And Piping(#51538-)
| 01***16 | Bolt,(For Slag Handling) | 4 |
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 4 |
Guard
Komatsu : D20q-5(S/N 45368-Up) : Guard : Cross Bar
| 01***40 | Bolt,(Not Used With Cab) | 8 |
| 01***45 | Bolt,(For Slag Handling) | 16 |
| 01***45 | Bolt, Fuel Tank Mounting - Front Right | 8 |
Komatsu : D20q-5(S/N 45368-Up) : Guard : Engine Bottom Guard
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 3 |
| 01***30 | Bolt,(For Center Guard) | 14 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 3 |
Komatsu : D20q-5(S/N 45368-Up) : Guard : Hitch
| 01***40 | Bolt | 2 |
| 01***45 | Washer,(Without R.O.P.S.) | 2 |
| 10***12 | Drawbar | 1 |
Komatsu : D20q-5(S/N 45368-Up) : Guard : Mark And Plate (Except Japan)
| 01***00 | ,Caution | 1 |
| 04***60 | Screw,Machine Model (For Ec Reg.) | 4 |
| 09***35 | Plate? Name,(Limited Supply) (English) | 1 |
Komatsu : D20q-5(S/N 45368-Up) : Guard : Mark And Plate (Except Japan) (Chinese)
| 04***60 | Screw,Machine Model (For Ec Reg.) | 4 |
| 09***00 | Plate? Safety,Inspection And Maintenance | 1 |
| 09***35 | Plate? Name,Ripper (Limited Supply) | 1 |
Komatsu : D20q-5(S/N 45368-Up) : Guard : Mark And Plate (Except Japan) (English)
| 04***60 | Screw,Machine Model (For Ec Reg.) | 4 |
| 09***00 | Plate? Safety,Inspection And Maintenance | 1 |
| 09***35 | Plate? Name,(Limited Supply) (English) | 1 |
Komatsu : D20q-5(S/N 45368-Up) : Guard : Operator'S Seat
| 01***25 | Bolt,(Without Auto Priming System) | 4 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 15 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Guard : Operator'S Seat (Op)
| 01***25 | Bolt,(Without Auto Priming System) | 4 |
| 01***16 | Bolt,(Sandy And Dusty Spec.) | 8 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 15 |
Komatsu : D20q-5(S/N 45368-Up) : Guard : Radiator Guard And Hood(#45368-51537)
Komatsu : D20q-5(S/N 45368-Up) : Guard : Radiator Guard And Hood(#51538-)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 11 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 2 |
| 01***35 | Bolt,(For Pedal Steering) | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Guard : Rear Cover And Hydraulic Tank
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***16 | Bolt,(Sandy And Dusty Spec.) | 1 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 25 |
Komatsu : D20q-5(S/N 45368-Up) : Guard : Side Frame And Floor Plate(#45368-50000)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 2 |
| 01***35 | Bolt,(For Pedal Steering) | 10 |
Komatsu : D20q-5(S/N 45368-Up) : Guard : Side Frame And Floor Plate(#50001-)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 2 |
| 01***35 | Bolt,(For Pedal Steering) | 10 |
Main Clutch And Transmission
Komatsu : D20q-5(S/N 45368-Up) : Main Clutch And Transmission : Counter Shaft And Gear
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 2 |
| 01***40 | Bolt,(Dust And Dirt Protection) | 3 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 3 |
Komatsu : D20q-5(S/N 45368-Up) : Main Clutch And Transmission : Gear Shift Lever And Fork
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***12 | Screw,(With Articulate Indicator) | 4 |
| 01***20 | Screw,Set | 3 |
Komatsu : D20q-5(S/N 45368-Up) : Main Clutch And Transmission : Inertia Brake
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 1 |
| 01***06 | Nut, Regular Hexagon (M8-1.25) | 5 |
Komatsu : D20q-5(S/N 45368-Up) : Main Clutch And Transmission : Intermadiate Shaft And Gear
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 3 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 3 |
Komatsu : D20q-5(S/N 45368-Up) : Main Clutch And Transmission : Main Clutch Case(#45368-50000)
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 3 |
| 01***25 | Bolt,(Without Auto Priming System) | 4 |
| 01***30 | Bolt,(Cold Terrain Spec.) | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Main Clutch And Transmission : Main Clutch Case(#50001-)
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***25 | Bolt,(Without Auto Priming System) | 4 |
| 01***30 | Bolt,(Cold Terrain Spec.) | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Main Clutch And Transmission : Main Clutch Pedal
| 01***30 | Bolt,(Cold Terrain Spec.) | 1 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 2 |
| 01***30 | Bolt,(For France Noise Suppression) | 3 |
Komatsu : D20q-5(S/N 45368-Up) : Main Clutch And Transmission : Main Clutch Plate
| 01***10 | Bolt, Mount Flasher | 6 |
| 01***16 | Bolt (Welded) | 6 |
| 01***16 | Bolt,(For Slag Handling) | 6 |
Komatsu : D20q-5(S/N 45368-Up) : Main Clutch And Transmission : Main Clutch Pump
| 04***15 | Ring, Snap | 1 |
| 07***01 | Pump Ass'Y (Fal10) | 1 |
| 07***60 | Seal,Oil | 1 |
Komatsu : D20q-5(S/N 45368-Up) : Main Clutch And Transmission : Main Clutch Pump Drive And Relief Valve
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***70 | Bolt, Spacer | 4 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 8 |
Komatsu : D20q-5(S/N 45368-Up) : Main Clutch And Transmission : Main Clutch Yoke
| 01***30 | Bolt,(For France Noise Suppression) | 2 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 1 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 3 |
Komatsu : D20q-5(S/N 45368-Up) : Main Clutch And Transmission : Main Shaft And Gear
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 3 |
| 01***10 | Nut | 1 |
| 01***10 | Nut | 1 |
Komatsu : D20q-5(S/N 45368-Up) : Main Clutch And Transmission : Transmission Case
| 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 : D20q-5(S/N 45368-Up) : Main Clutch And Transmission : Universal Joint
| 01***40 | Bolt,(For Position Fixing) | 8 |
| 01***25 | Washer,Spring?(Sandy And Dusty Spec.) | 8 |
| 07***75 | Fitting,Grease (Without Lub. Piping) | 1 |
Optional Parts
Komatsu : D20q-5(S/N 45368-Up) : Optional Parts : Back-Up Alarm
| 01***20 | Bolt,(Large Capacity Type) (Std) | 1 |
| 01***20 | Screw | 4 |
| 01***05 | Nut (Welded) | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Optional Parts : Brake Pedal And Linkage (For Lever Steering)(#45368-50000)
| 01***30 | Bolt,(Cold Terrain Spec.) | 1 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 3 |
| 01***30 | Bolt,(For France Noise Suppression) | 3 |
Komatsu : D20q-5(S/N 45368-Up) : Optional Parts : Bucket Lock
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***08 | Nut, Regular Hexagon (M10-1.50) | 4 |
| 01***13 | Nut,Plate (Welded) | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Optional Parts : Canopy
| 01***25 | Bolt - Rear Guard Mounting | 8 |
| 01***30 | Bolt,Radio Controlled Slag Handling | 4 |
| 01***10 | Nut,(Dust?Drip Proof? Trimming S.) | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Optional Parts : Counter Weight
| 01***15 | Nut,(For Slag Handling) | 6 |
| 01***45 | Washer,(Without R.O.P.S.) | 6 |
| 10***20 | Stud | 6 |
Komatsu : D20q-5(S/N 45368-Up) : Optional Parts : Dumping Fork
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
| 01***00 | Bolt (M10-1.50x100) | 2 |
| 01***11 | Nut,(Not Shown) | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Optional Parts : Head Guard
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 1 |
| 01***40 | Bolt,(Not Used With Cab) | 18 |
| 01***75 | Bolt,Dust | 24 |
Komatsu : D20q-5(S/N 45368-Up) : Optional Parts : Rops Canopy
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 1 |
| 01***40 | Bolt,(Not Used With Cab) | 26 |
| 01***45 | Bolt, Mount Center Hinge Retainer (Lower) | 8 |
Komatsu : D20q-5(S/N 45368-Up) : Optional Parts : Steering Lever And Linkage (For Lever Steering)(#45368-50000)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 5 |
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
| 01***06 | Nut? L.H. Thread,R.H. Thread | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Optional Parts : Steering Pedal And Linkage (For Pedal Steering)(#50001-50865)
| 01***30 | Bolt,(Cold Terrain Spec.) | 2 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 6 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Optional Parts : Steering Pedal And Linkage (For Pedal Steering)(#50866-)
| 01***30 | Bolt,(Cold Terrain Spec.) | 2 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 6 |
| 01***30 | Bolt,(For France Noise Suppression) | 8 |
Komatsu : D20q-5(S/N 45368-Up) : Optional Parts : Straight Dozer
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
| 01***00 | Bolt (M10-1.50x100) | 2 |
| 01***11 | Nut,(Not Shown) | 2 |
Steering System And Final Drive
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Bevel Gear And Shaft
| 01***16 | Bolt,(Sandy And Dusty Spec.) | 6 |
| 01***10 | Nut,(Dust?Drip Proof? Trimming S.) | 8 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Brake Band
| 01***35 | Bolt,(For Pedal Steering) | 8 |
| 01***42 | Washer,Spring (For Pedal Steering) | 8 |
| 01***23 | Plain Washer | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Brake Pedal And Linkage (For Lever Steering)(#50001-)
| 01***30 | Bolt,(Cold Terrain Spec.) | 1 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 3 |
| 01***30 | Bolt,(For France Noise Suppression) | 3 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Final Drive Gear
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 16 |
| 01***30 | Bolt,(For France Noise Suppression) | 8 |
| 01***20 | Bolt,(Used When Towing Winch) | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Final Drive Housing
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 16 |
| 01***30 | Bolt,Radio Controlled Slag Handling | 26 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 16 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Parking Brake Lever
| 01***30 | Bolt,(Cold Terrain Spec.) | 1 |
| 01***35 | Bolt,(Without Auto Priming System) | 1 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Sprocket And Shaft
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***11 | Nut (M14-1.50 Thd), Nut; Was 01582-01411 | 24 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 8 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Steering Case And Main Frame
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 16 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 8 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 16 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Steering Case Cover
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 24 |
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
| 01***35 | Bolt,(For Quick Shift) (Mitsubishi) | 20 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Steering Clutch
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 16 |
| 01***90 | Bolt (M10-1.50x90) | 8 |
| 01***10 | Nut,(For Slag Handling) | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Steering Lever And Linkage (For Lever Steering)(#50001-50865)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 5 |
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
| 01***06 | Nut? L.H. Thread,R.H. Thread | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Steering Lever And Linkage (For Lever Steering)(#50866-)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 1 |
| 01***30 | Bolt,(For France Noise Suppression) | 8 |
| 01***06 | Nut? L.H. Thread,R.H. Thread | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Steering Oil Piping(#50866-)
| 01***16 | Bolt,(For Slag Handling) | 1 |
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
| 01***40 | Bolt,(Dust And Dirt Protection) | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Steering Pedal And Linkage (For Pedal Steering)(#45368-50000)
| 01***30 | Bolt,(Cold Terrain Spec.) | 2 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 6 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Steering Valve (For Pedal Steering)(#50866-)
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***25 | Washer,Spring?(Sandy And Dusty Spec.) | 8 |
| 04***16 | Pin, Spring | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Steering Valve And Piping(#45368-50865)
| 01***20 | Bolt,(Large Capacity Type) (Std) | 4 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Steering System And Final Drive : Steering Valve(#50866-)
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***25 | Washer,Spring?(Sandy And Dusty Spec.) | 8 |
| 04***16 | Pin, Spring | 2 |
Tool And Kit
Komatsu : D20q-5(S/N 45368-Up) : Tool And Kit : Tool
| 07***00 | Pump,Grease | 1 |
| 07***00 | Pump,Grease | 1 |
| 07***00 | Pump,Grease | 1 |
Track
Komatsu : D20q-5(S/N 45368-Up) : Track : Carrier Roller
| 01***25 | Bolt,(Without Auto Priming System) | 3 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***25 | Washer,Spring?(Sandy And Dusty Spec.) | 3 |
Komatsu : D20q-5(S/N 45368-Up) : Track : Front Idler
Komatsu : D20q-5(S/N 45368-Up) : Track : Recoil Spring
| 01***16 | Bolt,(For Slag Handling) | 4 |
| 01***30 | Bolt,Radio Controlled Slag Handling | 8 |
| 01***35 | Bolt,(For Pedal Steering) | 20 |
Komatsu : D20q-5(S/N 45368-Up) : Track : Track Frame(#45368-47329)
| 01***20 | Bolt,(Large Capacity Type) (Std) | 16 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 24 |
| 01***25 | Bolt,(For Slag Handling) | 36 |
Komatsu : D20q-5(S/N 45368-Up) : Track : Track Frame(#47330-)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 24 |
| 01***25 | Bolt,(For Slag Handling) | 60 |
| 01***35 | Bolt,(For Pedal Steering) | 16 |
Komatsu : D20q-5(S/N 45368-Up) : Track : Track Roller
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 12 |
| 01***45 | Bolt, Mount Center Hinge Retainer (Lower) | 40 |
| 01***25 | Washer,Spring?(Sandy And Dusty Spec.) | 12 |
Komatsu : D20q-5(S/N 45368-Up) : Track : Track Shoe
| 01***18 | Nut? Shoe (Kit) | 296 |
| 10***01 | Shoe Bolt And Nut K.,(Except Swamp) | 1 |
| 10***20 | Link,Track? L.H | 74 |
Work Equipment
Komatsu : D20q-5(S/N 45368-Up) : Work Equipment : Bucket
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
| 01***00 | Bolt (M10-1.50x100) | 2 |
| 01***11 | Nut,(Not Shown) | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Work Equipment : Side Frame And Lift Arm
| 01***20 | Bolt,(Large Capacity Type) (Std) | 4 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 20 |
| 01***55 | Bolt,(For Long Track) | 12 |
Work Equipment Control System
Komatsu : D20q-5(S/N 45368-Up) : Work Equipment Control System : Bucket Dump Cylinder
| 01***20 | Bolt,(Large Capacity Type) (Std) | 1 |
| 01***30 | Bolt,(For France Noise Suppression) | 1 |
| 01***09 | Nut,(With Body Positioner) | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Work Equipment Control System : Bucket Lift Cylinder
| 01***20 | Bolt,(Large Capacity Type) (Std) | 1 |
| 01***45 | Bolt,(For Suction? Reversible Fan) | 1 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 1 |
Komatsu : D20q-5(S/N 45368-Up) : Work Equipment Control System : Hydraulic Control Lever
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***16 | Screw | 5 |
| 01***03 | Nut? L.H. Thread,L.H. Thread | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Work Equipment Control System : Hydraulic Control Valve (1/2)
| 01***16 | Bolt (Op) | 4 |
| 01***25 | Bolt, Seal Cover Mounting | 2 |
| 01***30 | Bolt | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Work Equipment Control System : Hydraulic Control Valve (2/2)
| 07***14 | O-Ring,(F4350-61a0a-20 ) | 4 |
| 07***34 | O-Ring, O-Ring,Drain Plug? R.H. Half Tank | 4 |
| 07***23 | O-Ring,(For 2nd Travel Speed) (Op) | 1 |
Komatsu : D20q-5(S/N 45368-Up) : Work Equipment Control System : Hydraulic Oil Piping (Pump - Valve)
| 01***45 | Bolt,(S6d155-4b) | 4 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 1 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Work Equipment Control System : Hydraulic Oil Piping (Valve - Dump Cylinder)(#45368-50000)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 2 |
| 01***11 | Nut,(With Under Mirror) | 8 |
Komatsu : D20q-5(S/N 45368-Up) : Work Equipment Control System : Hydraulic Oil Piping (Valve - Dump Cylinder)(#50001-)
| 01***20 | Bolt,(Large Capacity Type) (Std) | 4 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 2 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 2 |
Komatsu : D20q-5(S/N 45368-Up) : Work Equipment Control System : Hydraulic Oil Piping (Valve - Lift Cylinder)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 1 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 4 |
| 01***40 | Bolt,(Dust And Dirt Protection) | 4 |
Komatsu : D20q-5(S/N 45368-Up) : Work Equipment Control System : Hydraulic Oil Piping(#45368-50000)
| 04***15 | Ring, Snap | 1 |
| 70***00 | Pump Ass'Y,(See Fig. 3601a) | 1 |
| 70***10 | Seal, Oil | 1 |
Komatsu : D20q-5(S/N 45368-Up) : Work Equipment Control System : Hydraulic Oil Piping(#50001-)
| 04***15 | Ring, Snap | 1 |
| 70***10 | Seal, Oil | 1 |
| 70***70 | Plate | 1 |
Komatsu : D20q-5(S/N 45368-Up) : Work Equipment Control System : Hydraulic Tank And Filter
| 01***16 | Bolt,(For Slag Handling) | 7 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 3 |
| 01***06 | Nut, Regular Hexagon (M8-1.25) | 3 |
D20Q-5(S/N 45368-UP) serial number reference
The PIN plate is located on the front frame casting, typically on the operator's left side near the radiator support. To read the prefix, identify the characters preceding the sequential build number on the machine plate or chassis-stamped ID.
| Prefix | Identifies | Notes |
|---|---|---|
| 45368 | D20Q-5(S/N 4DIS-UP) | Serial range 45368-UP identifies the D20Q-5 crawler dozer. Production years are approximately 1979–1988. The machine utilizes a Komatsu 4D94 engine with a displacement of 2.94 L (0.78 US gal). Configuration features include a track width of 510 mm (20.1 in) and an operating weight of approximately 4.08 t (8,995 lb). |
Frequently asked questions
What engine is installed in the D20Q-5?
The machine is powered by a Komatsu 4D94 engine, delivering approximately 39 hp (29 kW) of net power.
What is the operating weight of this model?
The operating weight for the D20Q-5 is approximately 8,994.9 lb (4,080 kg).
What machine replaced the D20Q-5?
Specific successor models are not explicitly documented in the technical data; however, it belongs to the Komatsu D-series lineage of crawler dozers/loaders.
What D20Q-5(S/N 45368-UP) owners discuss
What are the known steering and clutch failure modes for this series?
Steering clutches may stick due to wear or contamination, leading to poor response. Operators have reported losing steering on both sides after 10–15 minutes of operation, with functionality returning only once the machine cools. The drive clutch may also exhibit intermittent disengagement, where it fails to disengage initially but functions correctly after running for a period.
What engine is installed in the D20Q-5 (S/N 45368-UP) and what are its key specs?
The machine uses a Komatsu 4D94 engine. Key specifications include a net power of approximately 38.9 hp to 39 hp (29 kW), a displacement of 179 cu in (3 L), and an engine speed at maximum torque of 2,450 rpm.
What undercarriage and ground pressure specifications should be expected?
The machine features a track width of 20.08 in (510 mm) and a track gauge of 58.67 in (1490 mm). Ground pressure is rated at approximately 3.41 psi (23.52 kPa), with 5 track rollers per side.
What electrical or sensor issues are common on Komatsu machines of this era?
Common fault codes can indicate low battery voltage, high coolant temperature, sensor failures, solenoid valve circuit issues, or abnormal pressure readings. Specifically, error code DAFRMC indicates a CAN communication error between the pump controller and engine controller.
What are the primary maintenance concerns regarding fluids?
Regularly monitor the cooling system fluid capacity, which is approximately 3.5 gal (13 L). For transmission and hydraulic health, check oil levels and inspect for debris that may indicate internal component wear. Use Komatsu genuine lubricants to meet engineering standards.
What should be checked when buying a used D20Q-5(S/N 45368-UP)?
Verify the exact serial range on the machine plate against parts catalogs. Check for any mismatch between the riveted chassis plate and the engraved frame number, as this is a primary signal of stolen equipment. Inspect the engine block near the injection pump to verify the engine serial matches the maintenance history.
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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