Komatsu S6D95L-1GG(S/N 58644-UP)
Maintenance schedule, common problems & OEM parts breakdown
The Komatsu S6D95L-1GG engine is a 6-cylinder, water-cooled, direct-injection diesel powerplant belonging to the 95 Series family. It is primarily configured for the FD60H, FD70H, and FD80H-5 series of heavy-duty forklifts. The engine features a 95 mm bore and 115 mm stroke, yielding a total displacement of 4,890 cm³. It delivers flywheel horsepower ranging from 82 to 110 HP depending on the specific machine application, with maximum torque between 28 and 41.5 kgm. The engine utilizes a Bosch VE distributor-type fuel pump and a mechanical all-speed governor. Production years for the FD60H/70H/80H-5 series generally align with the mid-1990s to early 2000s heavy equipment era. Predecessor lineage includes the 4D95L and 6D95L non-supercharged variants, while successor lines evolved into the SA6D107 and SAA6D107 series for higher torque and emissions compliance.
Across the 95 Series generations, the primary changes involved the integration of turbocharging and the transition from in-line to distributor-type fuel injection pumps to meet evolving performance standards. The S6D95L-1GG variant specifically denotes the turbocharged configuration used in the FD60H/70H/80H-5 models. This engine remains significant in the used and parts market due to its widespread installation in durable Komatsu forklifts and its mechanical simplicity, which allows for straightforward rebuilds. The availability of aftermarket components and the engine's robust cast-iron block construction make it a cost-effective power source for industrial material handling applications where Tier 4 emissions systems are not required.
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 S6D95L-1GG(S/N 58644-UP) specifications
Engine
| Model | S6D95L-1 (S6D95L-1GG S/N 58644-UP uses S6D95L-1 data) |
| Configuration | 6-cylinder in-line, 4-stroke, water-cooled, turbocharged diesel engine with mechanical control |
| Bore x Stroke | 95 mm x 115 mm (3.74 in x 4.53 in) |
| Displacement | 4.89 L (4,890 cm³) |
| Gross Power | 101 kW (135 HP) @ 2,200 rpm (SAE J1995) |
| Net Power | 95 kW (127 HP) @ 2,200 rpm (SAE J1349) |
| Maximum Torque | 454 N·m (335 lb·ft) @ 1,600 rpm |
| Emissions Tier | Pre-EPA Tier 1 / Pre-EU Stage I |
Weights
| Dry Weight (Engine Only) | 850–950 kg (1,874–2,094 lb) (varies by configuration/accessories) |
Dimensions
| Engine Length | 1,520 mm (59.8 in) |
| Engine Width | 880 mm (34.6 in) |
| Engine Height | 1,050 mm (41.3 in) |
Performance
| Fuel Consumption | ≤220 g/kW·h (at rated power) |
| Compression Ratio | 17.5:1 |
Service capacities (summary)
| Oil Capacity (incl. filter) | 22 L (23.2 qt) |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
S6D95L-1GG(S/N 58644-UP) fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine Crankcase (with filter) | 11 L (2.9 US gal) | Komatsu EO or equivalent diesel engine oil; viscosity varies by climate per factory spec sheet |
| Cooling System | 7.5 L (2.0 US gal) to 8.5 L (2.2 US gal) | Komatsu Super Coolant AF-NAC or equivalent ethylene glycol coolant |
| Fuel Tank | Not documented for this exact serial range — verify with your dealer | Not documented for this exact serial range — verify with your dealer |
| Transmission/Powertrain | Not documented for this exact serial range — verify with your dealer | Not documented for this exact serial range — verify with your dealer |
| Final Drives (each) | Not documented for this exact serial range — verify with your dealer | Not documented for this exact serial range — verify with your dealer |
| Hydraulic System and Tank | Not documented for this exact serial range — verify with your dealer | Not documented for this exact serial range — verify with your dealer |
| Axles/Differentials | Not documented for this exact serial range — verify with your dealer | Not documented for this exact serial range — verify with your dealer |
| Grease | N/A | Komatsu grease or equivalent lithium-based grease |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Komatsu S6D95L-1GG(S/N 58644-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 S6D95L-1GG(S/N 58644-UP) beyond the schedule
Predictive Maintenance & Fluid Analysis
Utilize Komatsu KOWA fluid analysis at every 500-hour interval to monitor engine wear metals (iron, copper, lead, aluminum) and contaminants. Check coolant pH, SCA concentration, and glycol content to prevent liner cavitation and corrosion. Monitor hydraulic oil particle count and viscosity to detect pump wear early. Track fuel dilution and soot levels in the engine oil to determine optimal drain intervals based on actual operating conditions rather than fixed hours alone.
Corrective & Common Repairs
Address Bosch VE distributor pump failures by inspecting the governor linkage and fuel delivery rates. Replace worn turbocharger seals if oil consumption increases or blue smoke appears. Inspect the mechanical all-speed governor for wear in the centrifugal weights. Check the 24V, 15A alternator brushes and voltage regulator for charging issues. Replace worn piston rings and cylinder liners if compression drops below specification or blow-by exceeds limits.
Overhaul & Rebuild Points
Rebuild the engine when cylinder bore wear exceeds 0.05 mm or taper exceeds 0.025 mm. Replace the crankshaft if journal radius wear is excessive or if cracks are found in the main bearing saddles. Inspect the cylinder head for warpage exceeding 0.05 mm and replace valve seats if recession exceeds 1.0 mm. Replace the timing gear case if gear backlash exceeds 0.20 mm. Rebuild the fuel injection pump if delivery pressure drops below factory specs.
Seasonal & Environment Servicing
In cold climates, use Komatsu EO or TO engine oil with the correct viscosity grade to ensure proper lubrication at startup. Check coolant freeze protection level before winter operations. In dusty environments, inspect the air filter restriction indicator more frequently and clean the outer element daily. Flush the radiator and oil cooler fins regularly to prevent overheating in high-temperature applications. Drain the fuel water separator daily to prevent microbial growth and injector damage.
S6D95L-1GG(S/N 58644-UP) common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 07281-00197 | Clamp,(With Pre-Fuel Filter) | Fuel system service | Check fitment → |
| 600-311-8221 | Cartridge,Engine Fuel Filter | Fuel system service | Check fitment → |
| 6204-71-6101 | Fuel Filter Ass'Y | Fuel system service | Check fitment → |
| 07000-02135 | O-Ring,Hydraulic Oil Filter | Hydraulic service | Check fitment → |
| 6204-61-5190 | Gasket,Oil Cooler Element | Lubrication service | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
S6D95L-1GG(S/N 58644-UP) fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| CA115 | Engine crankshaft speed sensor failure | Broken sensor, wiring issue, or connector corrosion | Replace the speed sensor and verify the voltage at the pin connector |
| CA111 | Internal engine controller fault | ECM hardware failure | Replace or reprogram the ECM |
| CA451 | Common rail pressure sensor feedback value too high | Malfunction in the rail sensor or actual overpressure condition | Diagnose the fuel rail pressure sensor or pump lines |
| CA441 | Battery voltage too low | Alternator or battery failure | Replace the alternator or battery and check the voltage regulator |
| CA442 | Battery voltage too high | Alternator or battery failure | Replace the alternator or battery and check the voltage regulator |
| CA122 | Intake air pressure high voltage | Sensor malfunction or wiring issue | Verify the intake pressure sensor and wiring |
| CA123 | Intake air pressure low voltage | Sensor short or airflow restriction | Check for a sensor short or an airflow restriction |
| CA153 | Intake air temperature sensor error | Sensor failure | Replace or test the IAT sensor |
| CA154 | Intake air temperature sensor error | Sensor failure | Replace or test the IAT sensor |
| CA234 | Engine overspeed | Throttle calibration issue, engine load cycle, or operator misuse | Verify throttle calibration, engine load cycle, or operator misuse |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
S6D95L-1GG(S/N 58644-UP) attachments & work tools
Standard Buckets
Typical sizes for the 20-ton class (PC200-5/PC220-5) range from 1.0 to 1.5 cubic meters (0.37 to 0.55 cubic yards). Factory configurations include standard digging, heavy-duty, and grading variants. Coupler systems are typically the Komatsu quick-attach style with side-pins or hydraulic lock pins.
Trenching Buckets
Narrow-width buckets (approx. 300-600 mm / 12-24 inches) are available for the PC200-5/PC220-5 series. These require a specific hydraulic circuit for the side-cutting or tilt function if equipped. Mounting uses the standard quick-attach interface compatible with the boom eye.
Ripper/Plow Attachments
Single-shank rippers or rear-mounted plows are offered for dozer variants (e.g., D31P/D31PX) sharing the S6D95L-1GG engine. Mounting is via the rear frame hitch points. Hydraulic rippers require a dedicated pilot line and control valve arrangement from the main pump.
Hydraulic Breaker/Hammer
Compatible with 2-4 ton class breakers (e.g., 150-250 kg / 330-550 lb). Requires a high-flow hydraulic kit (often 150-200 L/min / 40-53 gpm) and a pilot-operated control valve. Mounting uses the standard quick-attach system with a breaker pin.
Grading/Dozer Blades
For motor grader applications (GD511A-1) using the S6D95L-1GG, the standard 12-foot (3.66 m) moldboard is typical. Mounting is via the frame-mounted pivot points and hydraulic cylinders. No quick-attach coupler is used; the blade is fixed to the frame.
All S6D95L-1GG(S/N 58644-UP) assemblies by section
Every catalogued assembly group for the Komatsu S6D95L-1GG(S/N 58644-UP). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Cooling System
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cooling System : Corrosion Resistor And Piping
| 01***35 | Bolt | 2 |
| 01***65 | Bolt,(With Water Separator) | 3 |
| 01***08 | Nut,See Fig. K4010-04a0 | 2 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cooling System : Water Pump And Cooling Fan
| 01***35 | Bolt,(For Quick Shift) (Mitsubishi) | 6 |
| 01***16 | Screw | 5 |
| 01***20 | Screw | 2 |
Cylinder Block
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Block : Camshaft And Tappet
| 01***20 | Screw | 2 |
| 04***16 | Fitting Wedge | 1 |
| 62***10 | Tappet | 12 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Block : Crankshaft
| 01***45 | Bolt,Nylock | 1 |
| 01***16 | Bolt,(With Alternator Cover Type) | 6 |
| 61***20 | Collar,Taper | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Block : Cylinder Block
| 01***16 | Screw | 1 |
| 01***06 | Nut | 1 |
| 04***20 | Pin,Dowel (Welded) | 2 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Block : Flywheel And Flywheel Housing
| 01***30 | Bolt | 6 |
| 01***30 | Bolt - Lower Oil Cooler Outlet Tubemounting | 11 |
| 07***15 | Plug,(Used When Without Heater) | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Block : Front Cover And Gear
| 01***70 | Bolt,(For 75a Alternator) | 1 |
| 01***16 | Bolt | 2 |
| 01***16 | Screw | 2 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Block : Oil Pan
| 01***12 | Bolt,(Without R.P.C.U.) | 3 |
| 01***20 | Bolt,(Forwarded Individually Parts) | 30 |
| 01***25 | Bolt,(With Corrosion Resistor) | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Block : Piston And Connecting Rod
| 04***12 | Ring, Snap | 12 |
| 62***10 | Bolt | 2 |
| 62***41 | Piston (S) | 6 |
Cylinder Head
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Head : Air Cleaner (Dowble Element Type)
| 07***29 | Clamp | 2 |
| 08***01 | Indicator,Dust Indicator | 1 |
| 09***61 | Plate? Instruction,(Japanese-English) (Not Shown) | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Head : Air Cleaner (Single Element Type)
| 07***29 | Clamp | 2 |
| 08***01 | Indicator,Dust Indicator | 1 |
| 09***61 | Plate? Instruction,(Japanese-English) | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Head : Air Intake Manifold And Connection
| 01***12 | Bolt | 2 |
| 01***16 | Bolt,(With Alternator Cover Type) | 1 |
| 01***20 | Bolt,(For Japan Pc200) | 2 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Head : Cylinder Head
| 01***20 | Bolt, Hose Clamps (Inlet And Return Line Hoses) | 4 |
| 02***04 | Plug, Pipe | 1 |
| 07***08 | Plug, Expansion | 6 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Head : Cylinder Head Cover
| 01***20 | Bolt,(For Japan Pc200) | 1 |
| 04***50 | Screw | 4 |
| 07***80 | Clamp, Drain Hose | 3 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Head : Exhaust Manifold And Turbocharger
| 01***25 | Grub Screw | 4 |
| 01***90 | Bolt,(For Large Fan) | 12 |
| 07***08 | Plug,(For W/O. Corrosion Resistor) | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Head : Muffler And Connection
| 01***50 | Bolt,(With Service Valve R.H.) | 1 |
| 01***20 | Bolt, Hose Clamps (Inlet And Return Line Hoses) | 2 |
| 01***25 | Bolt, Mount Engine Oil Drain To Fuel Tank | 5 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Head : Rocker Arm
| 01***65 | Bolt,(For Alternator Bracket Mount) | 8 |
| 61***30 | Circlip | 2 |
| 62***20 | Spring | 5 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Cylinder Head : Turbocharger
| 62***40 | Turbocharger Ass'Y | 1 |
| GA***16 | Bolt | 6 |
| GA***63 | Housing,Turbine | 1 |
Electrical System
Komatsu : S6d95l-1gg(S/N 58644-Up) : Electrical System : Alternator (25a)
| 60***30 | Alternator A. (25a),(With Non Hardening Pulley) | 1 |
| KD***57 | Bearing,Ball? Front | 1 |
| KD***11 | Rear Bracket Ass'Y | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Electrical System : Alternator And Mounting (25a)
| 01***35 | Bolt,(Cold Weather Spec.) | 1 |
| 01***25 | Bolt,(With Corrosion Resistor) | 3 |
| 01***60 | Screw | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Electrical System : Alternator And Mounting (25a) (With Safety Cover Type)
| 01***40 | Bolt,(Cold Weather Spec.) | 1 |
| 01***25 | Bolt,(With Corrosion Resistor) | 3 |
| 01***60 | Screw | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Electrical System : Starting Motor (5.5kw)
| 60***20 | Starting Motor Ass'Y,(5.5kw) | 1 |
| KD***30 | Bracket,Center | 1 |
| KD***40 | Washer Ass'Y,(Not Shown) | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Electrical System : Starting Motor And Mounting (5.5kw)
| 01***16 | Bolt,(With Alternator Cover Type) | 1 |
| 01***25 | Bolt,(With Corrosion Resistor) | 1 |
| 01***30 | Bolt | 2 |
Engine Kit
Komatsu : S6d95l-1gg(S/N 58644-Up) : Engine Kit : Gasket Kit
| 01***12 | Washer,Lock? Injection Gear | 1 |
| 07***05 | O-Ring,(Not Used With Emergency Str.) (K2) | 1 |
| 07***35 | O-Ring,Hydraulic Oil Filter | 1 |
Fuel System
Komatsu : S6d95l-1gg(S/N 58644-Up) : Fuel System : Fuel Filter And Piping
| 01***25 | Bolt,(With Corrosion Resistor) | 2 |
| 01***60 | Bolt (M10-1.50x160) | 2 |
| 07***12 | Gasket,Mechanical Pump Piping | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Fuel System : Fuel Injection Pump (Feed Pump)
| DK***20 | Bolt, Joint | 1 |
| DK***00 | Valve,Check | 2 |
| DK***10 | Feed Pump Ass'Y,(Not Shown) | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Fuel System : Fuel Injection Pump (Governor) (1/2)
| DK***00 | Shim? 2.00mm,(High Altitude Spec.) | 0 |
| DK***00 | Adapter | 1 |
| DK***42 | Governor Ass'Y | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Fuel System : Fuel Injection Pump (Governor) (2/2)
| DK***40 | Gasket,Air Compressor | 2 |
| DK***00 | Nut,Cap | 1 |
| DK***20 | Cover | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Fuel System : Fuel Injection Pump (Pump) (1/2)
| 62***20 | Injection Pump Ass'Y | 1 |
| 62***21 | Injection Pump Ass'Y | 1 |
| DK***30 | Key,Woodruff | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Fuel System : Fuel Injection Pump (Pump) (2/2)
| DK***40 | Shim? 0.50mm, Shim, 0.50mm; Was Dk029311-0040 | 0 |
| DK***90 | Shim? 0.25mm, Shim, 0.25mm; Was Dk029311-0590 | 0 |
| DK***00 | Sleeve,Control | 6 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Fuel System : Fuel Injection Pump And Piping
| 01***35 | Stud | 4 |
| 01***25 | Screw | 4 |
| 01***12 | Bolt,(See Fig.0501) | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Fuel System : Fuel Nozzle And Spill Pipe
| 01***35 | Bolt, Mount Bracket To Floor | 6 |
| 01***14 | Bolt,(With Corrosion Resistor) | 2 |
| 07***80 | Clip | 13 |
Lubricating Oil System
Komatsu : S6d95l-1gg(S/N 58644-Up) : Lubricating Oil System : Lubricating Oil Cooler
| 01***25 | Bolt,(With Corrosion Resistor) | 18 |
| 01***06 | Nut | 4 |
| 07***12 | T/Plug, Plug,(For Power Tilt Mech Angle) | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Lubricating Oil System : Lubricating Oil Filter
| 60***41 | Cartridge,Engine? Oil Filter | 1 |
| 60***30 | Plate? Caution,Oil Filter And Bypass Filter | 1 |
| 62***10 | Nipple | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Lubricating Oil System : Lubricating Oil Pump And Suction Pipe
| 01***12 | Bolt,(See Fig.0501) | 1 |
| 01***16 | Screw | 5 |
| 01***25 | Bolt,(With Corrosion Resistor) | 1 |
Komatsu : S6d95l-1gg(S/N 58644-Up) : Lubricating Oil System : Turbocharger Lubricating Oil Piping
| 01***16 | Screw | 5 |
| 01***20 | Screw | 4 |
| 01***06 | Nut | 1 |
S6D95L-1GG(S/N 58644-UP) serial number reference
The engine serial number is stamped on the engine block, typically on the left side near the injection pump. The machine serial number is found on the chassis plate, located on the right-hand side of the cab on the lower frame for excavators. The engine model prefix (e.g., S6D95L-1GG) identifies the engine family and configuration, while the serial number (58644-UP) confirms the specific build range for parts compatibility.
| Prefix | Identifies | Notes |
|---|---|---|
| S6D95L-1GG | S6D95L-1GG | Engine model prefix for the specified range. The source text identifies the base model as S6D95L-1, with the GG suffix indicating the specific configuration variant for this serial range. No other 3-character PIN prefixes are listed for this engine in the provided sources. Verify with dealer for exact PIN plate location and prefix decoding on export models. |
Frequently asked questions
What is the engine displacement and configuration?
The Komatsu S6D95L-1GG is a 6-cylinder, in-line, water-cooled, direct-injection diesel engine with a total piston displacement of 4,890 cm³ (4.89 L). It features a 95 mm bore and 115 mm stroke.
What is the operating weight of the machine this engine powers?
The operating weight varies by configuration and series. The FD60H, FD70H, and FD80H-5 forklifts typically have operating weights ranging from 34,000 to 38,000 lb (15,422 to 17,237 kg) depending on the attachment package and counterweight.
What engine replaced the S6D95L-1GG in newer Komatsu models?
Newer Komatsu models have largely transitioned to the SAA6D107E-2 and SA6D107E-2 engines to meet higher torque requirements and stricter emissions standards. The S6D95L-1GG is part of the older 95 Series lineage.
What S6D95L-1GG(S/N 58644-UP) owners discuss
What are the power and torque specifications for the S6D95L-1 engine in the WA320-8 wheel loader application?
What are the common hydraulic behaviors and diagnostic patterns for Komatsu excavators using this engine family?
What are the typical undercarriage and wear patterns associated with this machine type?
What are the common electrical and sensor issues reported for this engine series?
What are the known engine quirks and maintenance requirements for the S6D95L-1 series?
What should be checked when buying a used machine with the S6D95L-1 engine?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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