Komatsubulldozersmall ( - d39)
Komatsu D21Q-5(S/N 45094-UP)
Maintenance schedule, common problems & OEM parts breakdown
The Komatsu D21Q-5 (S/N 45094-UP) is a compact crawler loader designed for light-duty material handling and small construction applications. This machine belongs to the D21 series, featuring a Komatsu 4D94 engine providing 39 hp (29.1 kW) of net power. It operates within an operating weight range of approximately 9,130 lb (4,141 kg) and is configured with a 0.6 yd³ (0.4 m³) heaped bucket capacity. The series includes various configurations such as the D21S-5 and D21Q-5, often utilized for landscaping and light earthmoving tasks.
Across the D21 generations, changes in dash-number series reflect evolving engine specifications, hydraulic performance, and emissions tiers. While older models focused on mechanical simplicity, later iterations integrated advanced telematics. In today's used market, the D21Q-5 remains a significant asset due to its high maneuverability and low operating costs compared to larger 70+ hp machines. It is highly valued for its durability in tight jobsite environments, though maintenance of protective covers is critical to prevent rust and component degradation.
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 D21Q-5(S/N 45094-UP) specifications
Engine
| Engine Model | 4D94 |
| Net Power | 39 hp (29.1 kW) |
| Displacement | 179 cu in (3 L) |
Weights
| Operating Weight | 9,130 lb (4,141.3 kg) |
Dimensions
| Length With Bucket On Ground | 11.31 ft in (3,445 mm) |
| Width To Outside Of Tracks | 6.57 ft in (2,000 mm) |
| Height To Top Of Cab | 7.17 ft in (2,185 mm) |
| Clearance At Full Height And Dump | 7.34 ft in (2,235 mm) |
| Reach At Dump Height | 2.17 ft in (660 mm) |
| Track Gauge | 58.67 in (1,490 mm) |
| Length Of Track On Ground | 5.53 ft in (1,685 mm) |
| Track Shoe Width | 20.08 in (510 mm) |
Performance
| Max Speed | 2.8 mph (4.4 km/h) |
| Breakout Force - Std Bucket | 8,950 lb (39.9 kN) |
| Static Tipping Load | 5,160 lb (2,340.6 kg) |
| Ground Pressure | 3.41 psi (23.52 kPa) |
Blades
| 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.
D21Q-5(S/N 45094-UP) fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine Crankcase (w/ filter) | not specified | Komatsu genuine diesel engine oil |
| Cooling System | 13 L (3.5 gal) | Komatsu super coolant |
| Fuel Tank | 60 L (15.9 gal) | not specified |
| Transmission/Powertrain | not specified | Komatsu powertrain oil |
| Final Drives (each) | not specified | Komatsu axle oil |
| Hydraulic System/Tank | not specified | Komatsu hydraulic oil |
| Grease | notER specified | not specified |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Komatsu D21Q-5(S/N 45094-UP) maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 50 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
Servicing the D21Q-5(S/N 45094-UP) beyond the schedule
Predictive Maintenance & Fluid Analysis
Utilize oil analysis and hydraulic sampling at 50-hour intervals to monitor engine and system health. For machines equipped with telematics, monitor fault codes and running hours independently of the dashboard meter to detect early wear. Regularly check cooling system fluid levels (approx. 13 L / 3.5 gal) and inspect for contamination in fuel and hydraulic lines to prevent pump damage.
Corrective & Common Repairs
Address potential steering issues by inspecting the hydraulic system for air or blown cylinder gaskets. Monitor the engine for stalling during blade operation, which may indicate hydraulic pressure drops. Be alert for steering glitches that resolve only after warming up, often related to hydraulic fluid viscosity or valve performance. Ensure all protective covers are cleaned to prevent dirt buildup and subsequent component corrosion.
Overhaul & Rebuild Points
Plan major service interventions at 2,000-hour milestones, focusing on engine valve adjustments and hydraulic oil replacement. Evaluate the undercarriage for wear on track rollers (5 per side) and track shoes (510 mm / 20.08 in width). When rebuilding, verify that all components match the specific serial range 45094-UP to ensure correct fitment of engine mounts and hydraulic fittings.
Seasonal & Environment Servicing
During cold weather operation, allow the machine to warm up thoroughly to resolve potential steering or hydraulic sluggishness. In dusty environments, increase frequency of air cleaner inspections and clean all protective covers to prevent debris from packing against the chassis. Ensure the cooling system is properly serviced with appropriate Komatsu coolant to manage thermal loads during high-intensity summer shifts.
D21Q-5(S/N 45094-UP) common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 07281-00197 | Clamp,(With Pre-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.
D21Q-5(S/N 45094-UP) attachments & work tools
Blades
Straight dozer configuration includes optional parts scheme. Specific blade types (S/SU/A) and VPAT availability are not documented for this exact serial range.
Rippers
Specific ripper configurations, such as multi-shank or single-shank options and weights, are not documented for this exact serial range.
Winches
Winch class and towing winch options are not specified in available technical documentation for the D21Q-5 (S/N 45094-UP).
Drawbars/counterweights
Specific drawbar or counterweight configurations are not documented for this exact serial range.
Cab/ROPS guarding options
Forestry or waste-specific guarding options are not listed in the provided technical specifications.
Hydraulic arrangement notes
The rear-side fill tube is for hydraulic fluid. Specific arrangements for front/rear tool hydraulics are not detailed.
All D21Q-5(S/N 45094-UP) assemblies by section
Every catalogued assembly group for the Komatsu D21Q-5(S/N 45094-UP). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Damper And Transmission
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : 1st Housing
| 01***22 | Bolt,(Cold Terrain Spec.) | 4 |
| 01***25 | Washer,Spring?(Sandy And Dusty Spec.) | 4 |
| 04***12 | Pin, Spring | 3 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : 1st Housing (For F3-R3 Transmission)
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***45 | Bolt | 10 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : 2nd Housing (For F3-R3 Transmission)
| 04***12 | Pin, Spring | 3 |
| 04***15 | Ring,Back-Up | 1 |
| 06***07 | Bearing,Ball | 1 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Damper
| 01***16 | Bolt,(For Slag Handling) | 6 |
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 10 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Forward And 2nd Housing
| 04***24 | Pin,Dowel (For No.3 Housing) | 2 |
| 04***12 | Pin, Spring | 3 |
| 04***20 | Ring, Snap | 1 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Forward And 3rd Housing (For F3-R3 Transmission)
| 04***24 | Pin,Dowel (For No.3 Housing) | 2 |
| 04***12 | Pin, Spring | 3 |
| 04***20 | Ring, Snap | 1 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Inching Pedal
| 01***20 | Bolt,(Large Capacity Type) (Std) | 2 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 2 |
| 01***30 | Bolt,(For France Noise Suppression) | 3 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Modulation Valve
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***60 | Bolt,(Without Alternator Bracket) | 3 |
| 01***70 | Bolt | 5 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Modulation Valve (For F3-R3 Transmission)
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***60 | Bolt,(Without Alternator Bracket) | 3 |
| 01***70 | Bolt | 5 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Reverse Housing
| 01***55 | Bolt,(For Trimming Dozer) | 7 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 1 |
| 01***25 | Washer,Spring?(Sandy And Dusty Spec.) | 7 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Reverse Housing (For F3-R3 Transmission)
| 01***55 | Bolt,(For Trimming Dozer) | 7 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 1 |
| 01***25 | Washer,Spring?(Sandy And Dusty Spec.) | 7 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Selector And Inching Valve
| 01***25 | Bolt,(Without Auto Priming System) | 2 |
| 01***45 | Bolt,(S6d155-4b) | 7 |
| 01***75 | Bolt,(See Fig.0142) | 4 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Selector And Inching Valve (For F3-R3 Transmission)
| 01***25 | Bolt,(Without Auto Priming System) | 2 |
| 01***45 | Bolt,(S6d155-4b) | 5 |
| 01***55 | Bolt,(For Trimming Dozer) | 3 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Tramsmission Control Lever
| 01***30 | Bolt,(Cold Terrain Spec.) | 3 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 2 |
| 01***20 | Screw | 4 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Transfer
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 2 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 6 |
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Transfer (For F3-R3 Transmission)
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 2 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 6 |
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Transmission Case
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 2 |
| 01***45 | Bolt,(S6d155-4b) | 1 |
| 01***55 | Bolt,(For Trimming Dozer) | 2 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Transmission Case (For F3-R3 Transmission)
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 2 |
| 01***35 | Bolt,(Without Auto Priming System) | 1 |
| 01***45 | Bolt,(S6d155-4b) | 2 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Transmission Control Lever
| 01***30 | Bolt,(Cold Terrain Spec.) | 3 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 2 |
| 01***20 | Screw | 4 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Transmission Control Linkage
| 01***30 | Bolt,(Cold Terrain Spec.) | 3 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 2 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Transmission Pump
| 11***70 | Pump Ass'Y | 1 |
| (1***0) | Transmission Ass'Y | 1 |
| (1***0) | Transmission Ass'Y | 1 |
Komatsu : D21q-5(S/N 45094-Up) : Damper And Transmission : Transmission Pump (For F3-R3 Transmission)
| 11***70 | Pump Ass'Y | 1 |
| (1***0) | Transmission Ass'Y | 1 |
| (1***0) | Transmission Ass'Y | 1 |
Komatsu : D21q-5(S/N 45094-Up) : Damper 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 |
Engine Related Parts And Electrical System
Komatsu : D21q-5(S/N 45094-Up) : Engine Related Parts And Electrical System : Air Cleaner Connection
| 07***09 | Clamp,(See Fig. K0210-16a0) | 2 |
| 10***60 | Boot | 1 |
| 10***70 | Pipe | 1 |
Komatsu : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-Up) : Engine Related Parts And Electrical System : Engine Mounting Parts : Unit_02_of_02
| 01***10 | Bolt | 4 |
| 10***20 | Cushion,Rear | 4 |
| 10***30 | Cushion,Front | 4 |
Komatsu : D21q-5(S/N 45094-Up) : Engine Related Parts And Electrical System : Engine Mounting Parts : Unit_01_of_02
| 01***10 | Bolt | 4 |
| 10***20 | Cushion,Rear | 8 |
| 11***20 | Washer | 4 |
Komatsu : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-Up) : Engine Related Parts And Electrical System : Fuel Tank? Additional Strainer And Piping : Unit_02_of_02
| 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 : D21q-5(S/N 45094-Up) : Engine Related Parts And Electrical System : Fuel Tank? Additional Strainer And Piping : Unit_01_of_02
| 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 : D21q-5(S/N 45094-Up) : Engine Related Parts And Electrical System : Instrument Panel : Unit_01_of_02
| 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 : D21q-5(S/N 45094-Up) : Engine Related Parts And Electrical System : Instrument Panel : Unit_02_of_02
| 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 : D21q-5(S/N 45094-Up) : Engine Related Parts And Electrical System : Oil Cooler And Piping
| 01***20 | Bolt,(Large Capacity Type) (Std) | 1 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 2 |
| 01***30 | Bolt,(For France Noise Suppression) | 2 |
Komatsu : D21q-5(S/N 45094-Up) : Engine Related Parts And Electrical System : Radiator And Piping : Unit_01_of_02
| 01***12 | Bolt (M8-1.25x12) | 3 |
| 01***16 | Bolt,(For Slag Handling) | 4 |
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
Komatsu : D21q-5(S/N 45094-Up) : Engine Related Parts And Electrical System : Radiator And Piping : Unit_02_of_02
| 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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-Up) : Guard : Hitch
| 01***40 | Bolt | 2 |
| 01***45 | Washer,(Without R.O.P.S.) | 2 |
| 10***12 | Drawbar | 1 |
Komatsu : D21q-5(S/N 45094-Up) : Guard : Mark And Plate (Except Japan) (For 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 : D21q-5(S/N 45094-Up) : Guard : Mark And Plate (Except Japan) (For 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 : D21q-5(S/N 45094-Up) : Guard : Mark And Plate (Except Japan) (For Std Spec.)
| 04***60 | Screw,Machine Model (For Ec Reg.) | 4 |
| 09***00 | Plate? Safety,Inspection And Maintenance | 1 |
| 09***16 | Plate,Bucket Lever Lock | 1 |
Komatsu : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-Up) : Guard : Radiator Guard And Hood : Unit_01_of_02
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 15 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 2 |
| 01***35 | Bolt,(For Pedal Steering) | 4 |
Komatsu : D21q-5(S/N 45094-Up) : Guard : Radiator Guard And Hood : Unit_02_of_02
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 11 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 2 |
| 01***35 | Bolt,(For Pedal Steering) | 4 |
Komatsu : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-Up) : Guard : Side Frame And Floor Plate : Unit_01_of_02
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 2 |
| 01***35 | Bolt,(For Pedal Steering) | 10 |
Komatsu : D21q-5(S/N 45094-Up) : Guard : Side Frame And Floor Plate : Unit_02_of_02
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 2 |
| 01***35 | Bolt,(For Pedal Steering) | 10 |
Optional Parts
Komatsu : D21q-5(S/N 45094-Up) : Optional Parts : Back-Up Alarm
| 01***20 | Bolt,(Large Capacity Type) (Std) | 1 |
| 01***20 | Screw | 4 |
| 01***05 | Nut (Welded) | 4 |
Komatsu : D21q-5(S/N 45094-Up) : Optional Parts : Brake Pedal And Linkage (For Lever Steering)
| 01***30 | Bolt,(Cold Terrain Spec.) | 1 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 3 |
| 01***30 | Bolt,(For France Noise Suppression) | 3 |
Komatsu : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-Up) : Optional Parts : Steering Lever And Linkage (For Lever Steering)
| 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 : D21q-5(S/N 45094-Up) : Optional Parts : Steering Pedal And Linkage (For Pedal Steering) : Unit_02_of_02
| 01***30 | Bolt,(Cold Terrain Spec.) | 2 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 6 |
| 01***30 | Bolt,(For France Noise Suppression) | 8 |
Komatsu : D21q-5(S/N 45094-Up) : Optional Parts : Steering Pedal And Linkage (For Pedal Steering) : Unit_01_of_02
| 01***30 | Bolt,(Cold Terrain Spec.) | 2 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 6 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
Komatsu : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-Up) : Steering System And Final Drive : Brake Pedal And Linkage (For Lever Steering)
| 01***30 | Bolt,(Cold Terrain Spec.) | 1 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 3 |
| 01***30 | Bolt,(For France Noise Suppression) | 3 |
Komatsu : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-Up) : Steering System And Final Drive : Steering Case And Main Frame
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 8 |
| 01***35 | Bolt,(For Quick Shift) (Mitsubishi) | 8 |
Komatsu : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-Up) : Steering System And Final Drive : Steering Clutch
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 16 |
| 01***90 | Bolt (M10-1.50x90) | 8 |
| 01***90 | Bolt,(For Long Lift Arm) | 8 |
Komatsu : D21q-5(S/N 45094-Up) : Steering System And Final Drive : Steering Lever And Linkage (For Lever Steering) : Unit_01_of_02
| 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 : D21q-5(S/N 45094-Up) : Steering System And Final Drive : Steering Lever And Linkage (For Lever Steering) : Unit_02_of_02
| 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 : D21q-5(S/N 45094-Up) : Steering System And Final Drive : Steering Oil Piping
| 01***16 | Bolt,(For Slag Handling) | 1 |
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
| 01***40 | Bolt,(Dust And Dirt Protection) | 4 |
Komatsu : D21q-5(S/N 45094-Up) : Steering System And Final Drive : Steering Pedal And Linkage (For Pedal Steering)
| 01***30 | Bolt,(Cold Terrain Spec.) | 2 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 6 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
Komatsu : D21q-5(S/N 45094-Up) : Steering System And Final Drive : Steering Valve
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***25 | Washer,Spring?(Sandy And Dusty Spec.) | 8 |
| 04***16 | Pin, Spring | 2 |
Komatsu : D21q-5(S/N 45094-Up) : Steering System And Final Drive : Steering Valve (For Pedal Steering)
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***25 | Washer,Spring?(Sandy And Dusty Spec.) | 8 |
| 04***16 | Pin, Spring | 2 |
Komatsu : D21q-5(S/N 45094-Up) : Steering System And Final Drive : Steering Valve And Piping
| 01***20 | Bolt,(Large Capacity Type) (Std) | 4 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
Tool And Kit
Komatsu : D21q-5(S/N 45094-Up) : Tool And Kit : Tool
| 07***00 | Pump,Grease | 1 |
| 07***00 | Pump,Grease | 1 |
| 07***00 | Cartridge,Grease | 1 |
Track
Komatsu : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-Up) : Track : Front Idler
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 12 |
| 01***30 | Bolt,(For France Noise Suppression) | 8 |
| 01***08 | Nut,R.H. Thread | 2 |
Komatsu : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-Up) : Track : Track Frame : Unit_02_of_02
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 24 |
| 01***25 | Bolt,(For Slag Handling) | 60 |
| 01***35 | Bolt,(For Pedal Steering) | 16 |
Komatsu : D21q-5(S/N 45094-Up) : Track : Track Frame : Unit_01_of_02
| 01***20 | Bolt,(Large Capacity Type) (Std) | 16 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 24 |
| 01***25 | Bolt,(For Slag Handling) | 36 |
Komatsu : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-Up) : Work Equipment Control System : Hydraulic Oil Piping (Valve - Dump Cylinder) : Unit_01_of_02
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 2 |
| 01***11 | Nut,(With Under Mirror) | 8 |
Komatsu : D21q-5(S/N 45094-Up) : Work Equipment Control System : Hydraulic Oil Piping (Valve - Dump Cylinder) : Unit_02_of_02
| 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 : D21q-5(S/N 45094-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 : D21q-5(S/N 45094-Up) : Work Equipment Control System : Hydraulic Oil Pump : Unit_01_of_02
| 04***15 | Ring, Snap | 1 |
| 70***00 | Pump Ass'Y,(See Fig. 3601a) | 1 |
| 70***10 | Seal, Oil | 1 |
Komatsu : D21q-5(S/N 45094-Up) : Work Equipment Control System : Hydraulic Oil Pump : Unit_02_of_02
| 04***15 | Ring, Snap | 1 |
| 70***10 | Seal, Oil | 1 |
| 70***10 | Pump Ass'Y,(See Fig. 3601) | 1 |
Komatsu : D21q-5(S/N 45094-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 |
D21Q-5(S/N 45094-UP) serial number reference
The PIN plate is located on the front frame casting, typically near the operator's left side. To read the prefix, identify the first three characters of the serial number sequence provided on the chassis plate.
| Prefix | Identifies | Notes |
|---|---|---|
| D21 | D21Q-5 (S/N 45094-UP) | Identifies the crawler dozer family and size class. The numeric portion encodes the weight or horsepower class of the machine. |
Frequently asked questions
What engine is installed in the D21Q-5 (S/N 45094-UP)?
The machine is powered by a Komatsu 4D94 engine with a displacement of approximately 3 L (179 cu in).
What is the operating weight of this model?
The operating weight for the D21Q-5 is approximately 9,130 lb (4,141 kg).
What machine replaced the D21Q-5?
Specific successor model information for this exact serial range is not documented in the provided sources; however, the D21 series follows a dash-number generation lineage.
What D21Q-5(S/N 45094-UP) owners discuss
What are the common hydraulic troubleshooting symptoms for the D21Q-AT?
Operators have reported engine stalling when pulling back control levers. Additionally, following a blade cylinder gasket failure, air entering the hydraulic system is a known concern that can cause similar performance issues.
What specific steering issue has been documented for this machine series?
Steering failure has been linked to stuck clutches. In some related D21 configurations, steering glitches on one side may occur but often resolve once the equipment reaches operating temperature.
What maintenance concern is associated with Komatsu's protective covers?
Protective covers used to shield vulnerable components can pack with dirt. This accumulation leads to rust and significant degradation of both the covers and the underlying parts.
What are the engine specifications for the D21Q-5 (S/N 45094-UP)?
The machine is equipped with a Komatsu 4D94 engine. It produces 39 hp (29.1 kW) net power and has a displacement of 179 cu in (3 L).
What should be checked when inspecting the undercarriage of a D21Q-5?
Check for wear on the five track rollers per side and ensure the 510 mm (20.08 in) track shoe width is within spec. For LGP configurations, note that wide pads provide less traction for dozing compared to standard setups.
What are the critical checks when buying a used D21Q-5 (S/N 45094-UP)?
Verify the serial number on the front frame casting against the machine plate; a mismatch is a primary signal of stolen equipment. Additionally, check for any gaps between recorded hours and the dashboard hour-meter, as a discrepancy of more than 50 hours may indicate hour-meter rollback.
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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