Caterpillarengine - marinemarine engine
Caterpillar D326F
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar D326F is a vintage mechanical marine diesel engine, an inline 6-cylinder built before Caterpillar moved to electronic engine controls. It sits in the D318/D320/D326 family of Cat industrial and marine engines and is the naturally aspirated member of that line, which sets it apart from its Roots-blown D337 sibling; the two share service, parts, and reduction-gear documentation. Cat identifies D326F engines by serial number prefixes 39B1-up and 40B1-up. No published bore, stroke, displacement, horsepower, RPM, dry weight, or fluid-capacity figures survive in accessible factory literature for this model, so treat any such number found elsewhere as unverified until confirmed against the engine's own OMM or dealer records. The engine was offered for marine propulsion, driving the shaft through a reverse-reduction gear, and for marine auxiliary or generator duty; no work-tool or attachment lineup applies, since this is a fixed propulsion/auxiliary power unit rather than a mobile machine.
Caterpillar's mechanical D3xx marine and industrial engines spanned several bore sizes and aspiration choices through the 1950s and 1960s, with naturally aspirated, turbocharged, and Roots-blown variants sharing casting families and combustion-chamber design across the D326, D330, D333, D334, D336, and D337 line. No documented predecessor or successor specifically tied to the D326F has surfaced, so its place in that lineup is best treated as unconfirmed rather than assumed. One design detail did carry forward: the precombustion-chamber layout was reused in Caterpillar's 1Y73 SCOTE single-cylinder oil test engine, still referenced in ASTM/SAE lubricant testing literature. Today the D326F matters mainly to the vintage commercial-marine and collector market, where surviving units are kept running through reconditioned precombustion chambers, custom-sourced injectors, and salvaged parts shared with the D330/D333/D337 siblings rather than new-production Cat parts.
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.
Caterpillar D326F specifications
Engine
| Model / arrangement | D326 diesel engine, marine arrangement D326F. Part of Caterpillar's early mechanical-diesel D318 / D320 / D326 engine group, a related but distinct family from the smaller D311/D315 and larger D330/D333/D337/D339 groups. |
| Configuration | Inline 6-cylinder, mechanical (pre-electronic, jerk-pump/unit-injector era) diesel. |
| Gross/net power | Not documented in publicly available literature for this exact marine arrangement. No factory rating figure could be independently verified — check the engine data plate or the original operator's manual for the confirmed serial range. |
| Displacement | Not documented for this exact arrangement in publicly available sources. |
| Emissions tier | Not applicable. This is a pre-emissions-era mechanical diesel, predating any regulated emissions tier or Tier/Stage certification scheme. |
Weights
| Operating / shipping weight | Not documented in publicly available sources for this arrangement. |
| Ground pressure | Not applicable — this is a standalone marine propulsion/auxiliary engine, not a ground-contact machine. |
Dimensions
| Length / width / height | Not documented in publicly available sources for this arrangement. |
| Other class-relevant dimensions | No published dimensional data located for the D326F marine block, oil pan, or flywheel housing configuration. |
Performance
| Travel speed / drawbar figures | Not applicable. The D326F is a marine propulsion/auxiliary power engine, not a mobile machine — no travel speed, dig, lift, or drawbar figures apply. |
| Rated speed (RPM) | Not documented in publicly available sources for this exact arrangement. |
Service capacities (summary)
| Fuel tank | Not documented — fuel tank sizing for marine installs is typically vessel-specific and set by the boat builder, not the engine arrangement. |
| Engine oil | Not documented in publicly available sources for this arrangement. |
| Cooling system | Not documented in publicly available sources for this arrangement. Confirm raw-water/heat-exchanger configuration and coolant capacity against the data plate and original operator's manual. |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
D326F fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with oil filter) | Not documented in publicly available literature for this exact engine/serial range — verify against the D326F operation & maintenance manual or dealer parts book before servicing. | Not confirmed by name for this specific engine. This vintage industrial/marine diesel line (shares service literature with the sibling D337 engine) predates Caterpillar's modern branded oil line (Cat DEO); period lubrication charts for this generation call for a straight-viscosity diesel engine oil graded to ambient temperature at the installation. Confirm exact grade and brand spec against the engine dataplate and OMM. |
| Cooling system (jacket water / raw-water circuit) | Not documented in publicly available literature for this exact engine/serial range — capacity varies with the boatbuilder's cooling loop and heat-exchanger configuration; verify against the OMM. | Not confirmed by name for this specific engine. General practice for raw-water-cooled marine diesels of this vintage is a fresh-water jacket circuit dosed with a corrosion inhibitor; confirm the exact coolant/inhibitor spec named in the OMM rather than assuming a modern Cat ELC-era product, since this predates that line. |
| Fuel system | No integral fuel tank is part of the engine package — tank sizing is set by the vessel installation, not the engine OMM. | Clean, water-free diesel fuel meeting the fuel specification current at the time of the engine's OMM printing. No brand-name Cat fuel product applies; use the fuel grade and cleanliness limits stated in the OMM fuel-system section. |
| Grease points (water pump, linkages, and other fittings) | Spec only — no reservoir capacity applies; lubricate per the OMM's grease-point schedule. | General-purpose chassis grease per the OMM's stated NLGI grade; specific brand name not confirmed for this engine in available sources. |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar D326F maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 4,000 h |
|
| Every 10,000 h |
|
Servicing the D326F beyond the schedule
Predictive Maintenance & Fluid Analysis
With no ECM or fault-code system, predictive maintenance on the D326F relies on physical inspection and oil sampling rather than onboard diagnostics. Pull an oil sample at every filter change and watch for rising iron or copper, an early sign of precombustion-chamber or bearing wear on this mechanical design. Track injector pop-off pressure and spray pattern by hand. On raw-water-cooled units, sample and treat the raw-water side to slow corrosion in the heat exchanger and manifold, and log zinc anode consumption as a wear trend.
Corrective & Common Repairs
Most corrective work on the D326F centers on the precombustion chambers and injectors, the known wear points on this mechanical design; expect carbon erosion and pop-off drift well before any bottom-end trouble shows. Injector and precombustion-chamber parts are hard to source new, so many owners recondition existing units or pull good cores from D330/D333/D337 siblings. Raw-water pump impellers and reverse-reduction gear seals are the other common failure points on marine installations, driven by saltwater exposure rather than duty-cycle hours.
Overhaul & Rebuild Points
A D326F overhaul is a full-teardown job, not a top-end refresh, given the engine's age and the scarcity of exact-fit parts. Inspect the block and head for cracking around the precombustion-chamber bores before committing to a rebuild, since this is the family's known failure zone. Replace main and rod bearings, liners, and injectors as matched sets rather than piecemeal to keep the mechanical fuel system balanced across cylinders. Rebuild or replace the reverse-reduction gear, then recalibrate governor and injection timing before returning the engine to service.
Seasonal & Environment Servicing
Raw-water cooling makes seasonal servicing critical on the D326F: drain and flush the raw-water side before winter lay-up to prevent freeze cracking of the block, manifold, or heat exchanger. Check and replace zinc anodes at haul-out, since saltwater duty consumes them faster than fresh water. Before recommissioning, clear the sea strainer, inspect the raw-water pump impeller for winter-set cracking, and prime the mechanical fuel system before the first start. Inland or freshwater installations still need the same corrosion checks, just on a longer interval.
D326F common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 1H-1444 | Transfer--Oil Filter Instructions--1 7/8" High | Lubrication service | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
D326F attachments & work tools
Work-tool / attachment ecosystem
D326F is a standalone marine propulsion and auxiliary-power engine, not a mobile machine. There is no bucket, blade, coupler, or ground-engaging work-tool lineup for this class - reporting that ecosystem would be inaccurate for a marine block.
Marine reverse/reduction gear
Caterpillar published a dedicated reverse and reduction gear reference manual covering the D326 and D337 engines together, confirming a factory-matched marine gearbox pairing existed for this engine. Specific gear ratios and model numbers are not documented in general references - confirm against the unit's own reduction-gear tag or dealer records.
Cooling system arrangement
Engines of this generation (the 1947-era D311/D315/D318 family that D326 belongs to) were offered with raw-water heat-exchanger cooling as the typical marine setup, with keel-cooled arrangements used on some vessel installations. No D326-specific cooling-package breakdown is documented separately from the shared D326/D337 service literature.
Generator-end / auxiliary power configuration
Sibling engines in the same mechanical-injection D3xx family (D330/D333/D334/D336) were factory-offered in industrial and marine gen-set form. No source ties a specific generator-end package directly to the D326 by name, so treat gen-set fitment for this exact model as unconfirmed - verify with a dealer or the engine's build tag.
Control panel / instrumentation
No D326-specific control-panel variant is documented. As a mechanical, non-ECM engine of its era, expect a basic analog instrument panel (oil pressure, water temperature, tachometer) rather than electronic engine monitoring.
All D326F assemblies by section
Every catalogued assembly group for the Caterpillar D326F. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Attachments
3f9847 Tachometer Dual Drive Joint
| 3F***47 | Adapter As-Drive | 1 |
1l9517 Air Actuated Control And Panel Arrangement--R.H.
| 1L***61 | Air Actuated Control Group | 1 |
| 1L***47 | Instrument Panel Group | 1 |
| 1L***17 | Air Actuated Control And Panel Arrangement | 1 |
1l9518 Air Actuated Control And Panel Arrangement--
| 1L***62 | Air Actuated Control Group | 1 |
| 1L***84 | Instrument Panel Group | 1 |
| 1L***18 | Air Actuated Control And Panel Arrangement | 1 |
1l9520 Air Actuated Control And Panel Arrangement--L.H.
| 1L***84 | Instrument Panel Group | 1 |
| 1L***56 | Air Actuated Control Group | 1 |
| 1L***20 | Air Actuated Control And Panel Arrangement | 1 |
1l8761 Air Actuated Control Group--R.H.
| 0S***91 | Screw,Cap,Hexagon Bearing Retainer; Part Of Kit P/N 1w***82 | 4 |
| 1L***07 | Governor Pneumatic Actuator Group | 1 |
| 1L***51 | Bracket--Actuator To Governor | 1 |
1l8762 Air Actuated Control Group--L.H.
| 1L***65 | Washer--Bracket To Manifold | 1 |
| 1L***07 | Governor Pneumatic Actuator Group | 1 |
| 1L***46 | Link--Actuator To Lever | 1 |
1l9156 Air Actuated Control Group--L.H.
| 1L***65 | Washer--Bracket To Manifold | 1 |
| 1L***07 | Governor Pneumatic Actuator Group | 1 |
| 1L***46 | Link--Actuator To Lever | 1 |
3l2876 Air Actuated Control Group--L.H.
| 0S***88 | Bolt,Machine; Hose Assembly Mounting,Hose Assembly To Transmission,And To Torque Converter | 1 |
| 0S***94 | Bolt (1 In. Long 3/8 In. Dia.); Plate Assembly To Support Assembly | 4 |
| 1A***57 | Pin--Yoke End | 1 |
3l2309 Air Actuator Control Group--R.H.
| 3L***09 | Air Actuator Control Group; Air Actuated Control Group | 1 |
3h5271 Air Compressor
| 3H***71 | Air Compressor | 1 |
4l832 Air Compressor--12 Cubic Foot
| 4L***32 | Air Compressor | 1 |
4l840 Air Compressor Arrangement
| 1L***55 | Air Compressor Drive Group | 1 |
| 4L***40 | Air Compressor Arrangement | 1 |
| 4L***52 | Air Compressor Group; Air Compressor Mounting Group | 1 |
1l9838 Air Compressor Arrangement
| 1L***55 | Air Compressor Drive Group | 1 |
| 1L***82 | Air Compressor Group | 1 |
| 1L***38 | Air Compressor Arrangement | 1 |
1l8955 Air Compressor Drive Group
| 1L***55 | Air Compressor Drive Group | 1 |
4l852 Air Compressor Mounting Group--Type 3
| 4L***52 | Air Compressor Group; Air Compressor Mounting Group | 1 |
1l9482 Air Compressor Group--Field Installation--Type 2
| 1L***82 | Air Compressor Group | 1 |
4l852 Air Compressor Group--Type 1
| 4L***52 | Air Compressor Group; Air Compressor Mounting Group | 1 |
4l852 Air Compressor Mounting Group--Type 2
| 4L***52 | Air Compressor Group; Air Compressor Mounting Group | 1 |
1l9482 Air Compressor Group--Type 1
| 1L***82 | Air Compressor Group | 1 |
3l517 Air Motor--Type 1
| 3L***17 | Air Motor | 1 |
3l517 Air Motor--Type 2
| 3L***17 | Air Motor | 1 |
1l7415 Air Motor Assembly
| 1L***15 | Air Motor Assembly | 1 |
1l7415 Air Motor Assembly--Type 2
| 1L***15 | Air Motor Assembly | 1 |
1l9935 Air Starting Motor Group--Type 1
| 1L***35 | Air Starting Motor Group | 1 |
1l9935 Air Starting Motor Group--Type 2
| 1L***35 | Air Starting Motor Group | 1 |
1l9936 Air Starting System Arrangement
| 1L***97 | Fuel Priming Pump Group | 1 |
| 1L***35 | Air Starting Motor Group | 1 |
| 1L***36 | Air Starting System Arrangement | 1 |
3h756 Ammeter Group--Pilot House Mounted
| 3H***56 | Ammeter Group | 1 |
1l8954 Auxiliary Drive Group
| 1L***54 | Auxiliary Drive Group | 1 |
9f2068 Battery Group--24 Volt, 170 Ampere Hour
| 9F***68 | Battery Group | 1 |
1l5664 Battery Group--24 Volt, 120 Ampere Hour
| 1L***64 | Battery Group | 1 |
1l5662 Battery Group--30 Volt, 120 Ampere Hour
| 1L***62 | Battery Group | 1 |
1h1341 Battery Group--24 Volt, 200 Ampere Hour
| 1H***41 | Battery Group | 1 |
1l5663 Battery Group--30 Volt, 170 Ampere Hour
| 1L***63 | Battery Group | 1 |
2l1042 Bilge Pump And Auxiliary Drive Arrangement
| 1L***54 | Auxiliary Drive Group | 1 |
| 2L***42 | Bilge Pump And Auxiliary Drive Arrangement | 1 |
| 2L***43 | Bilge Pump Group | 1 |
2l1044 Bilge Pump Group
| 2L***44 | Bilge Pump Group | 1 |
2l1043 Bilge Pump Group
| 2L***43 | Bilge Pump Group | 1 |
9h6160 Camshaft And Governor Group
| 9H***60 | Camshaft And Governor Group | 1 |
Camshaft, Crankshaft, Connecting Rod And Piston
5h1227 Carburetor Assembly
| 5H***27 | Carburetor | 1 |
9h6181 Carburetor Assembly
| 9H***81 | Carburetor Assembly | 1 |
2f8223 Clutch Assembly
| 2F***23 | Clutch As | 1 |
8b243 Clutch Assembly--Type 2
| 8B***43 | Clutch Assembly | 1 |
8b243 Clutch Assembly--Type 1
| 8B***43 | Clutch Assembly | 1 |
7h1726 Clutch Group
| 7H***26 | Clutch Group | 1 |
7h997 Clutch Group--Starting Engine
| 7H***97 | Clutch Group | 1 |
5h7090 Clutch Group--Starting Engine
| 5H***90 | Clutch Group | 1 |
7h1710 Common Lubrication Oil System Conversion Group
| 7H***10 | Common Lubrication Oil System Conversion Group | 1 |
Connecting Rod And Piston--2 Required
1l8755 Positive Locking Control Group--Type 1
| 1L***55 | Control Group; Positive Locking Control Group | 1 |
2l218 Control Group
| 2L***18 | Control Group | 1 |
1l8755 Control Group--Positive Locking--R.H.--Type 2
| 1L***55 | Control Group; Positive Locking Control Group | 1 |
Crankshaft
Cylinder Block, Cylinder Head And Valve Mechanism--Part 2 Of 2
5h2547 Cylinder Block, Cylinder Head And Valve Mechanism--Part 1 Of 2
| 5H***47 | Cylinder Block Cylinder Head And Valve Mechanism; Cylinder Block, Cylinder Head And Valve Mechanism Group | 1 |
5h2547 Cylinder Block, Cylinder Head And Valve Mechanism--Part 2 Of 2
| 5H***47 | Cylinder Block Cylinder Head And Valve Mechanism; Cylinder Block, Cylinder Head And Valve Mechanism Group | 1 |
Cylinder Block, Cylinder Head And Valve Mechanism--Part 1 Of 2
9f740 Discharger
| 9F***40 | Discharger Group | 1 |
1l9100 Electric Starting Arrangement--32 Volt
| 1L***97 | Fuel Priming Pump Group | 1 |
| 1L***99 | Electric Starting Motor Group | 1 |
| 1L***00 | Electric Starting Arrangement | 1 |
2l355 Electric Starting Group--6 Volt
| 2L***55 | Electric Starting Group | 1 |
2l355 Electric Starting Group--6 Volt--Type 2
| 2L***55 | Electric Starting Group | 1 |
1l9552 Electric Starting Motor--32 Volt
| 1L***52 | Electric Starting Motor | 1 |
2l353 Electric Starting Motor--6 Volt
| 2L***53 | Electric Starting Motor | 1 |
1l9099 Electric Starting Motor Group--32 Volt
| 1L***99 | Electric Starting Motor Group | 1 |
4l1689 Electric Tachometer Group--Replaces 1l6461
| 4L***89 | Electric Tachometer Group | 1 |
4l1714 Electric Tachometer Group
| 1F***90 | Tachometer Drive Group | 1 |
| 4L***89 | Electric Tachometer Group | 1 |
| 4L***14 | Electric Tachometer Group | 1 |
1l6461 Electric Tachometer Group
| 1L***61 | Electric Tachometer Group | 1 |
2l5138 Electric Tachometer Group
| 2L***38 | Electric Tachometer Group | 1 |
3l4438 Electric Tachometer Group
| 3L***38 | Electric Tachometer Group | 1 |
4l1713 Electric Tachometer Group
| 3L***10 | Tachometer Drive Group | 1 |
| 4L***89 | Electric Tachometer Group | 1 |
| 4L***13 | Electric Tachometer Group | 1 |
Engine Support
7h1727 Engine Support Group
| 7H***27 | Engine Support Group | 1 |
2l306 Ether Starting Aid Group--L.H.
| 2L***06 | Ether Starting Aid Group--L.H. | 1 |
2l305 Ether Starting Aid Group--R.H.
| 2L***05 | Ether Starting Aid Group--R.H. | 1 |
2l5874 Ether Starting Aid Group--R.H.
| 2L***74 | Ether Starting Aid Group--R.H. | 1 |
4l3615 Exhaust Fitting Group
| 4L***15 | Exhaust Fitting Group | 1 |
1l9108 Flexible Fuel Lines
| 1L***08 | Flexible Fuel Lines | 1 |
2l474 Front Power Take-Off Group (2.8 : 1 Ratio) Clockwise Rotation
| 2L***74 | Front Power Take-Off Group | 1 |
2l475 Front Power Take-Off Group (1 : 1 Ratio) Counterclockwise Rotation
| 2L***75 | Front Power Take-Off Group | 1 |
1l9097 Fuel Priming Pump Group
| 1L***97 | Fuel Priming Pump Group | 1 |
2h7161 Fuel System Group
| 2H***61 | Fuel System Group | 1 |
2l7217 Gasoline Starting Engine Arrangement
| 0S***92 | Bolt--Cover To Flywheel Housing | 3 |
| 2B***57 | Plug (.375" Pipe Thread) | 1 |
| 2H***61 | Fuel System Group | 1 |
1l3205 Generator--32 Volt, 15 Ampere
| 1L***05 | Generator | 1 |
8h1963 Generator--6 Volt, 40 Ampere--Replaces 9f5094
| 8H***63 | Generator | 1 |
8f3333 Generator--6 Volt, 18 Ampere
| 8F***33 | Generator | 1 |
6f9461 Generator--12 Volt, 40 Ampere
| 6F***61 | Generator | 1 |
1h1920 Generator--12 Volt, 10 Ampere
| 1H***20 | Generator | 1 |
9f5094 Generator--6 Volt, 40 Ampere
| 9F***94 | Generator | 1 |
1l8967 Generator Arrangement--6 Volt, 18 Ampere
| 1L***54 | Auxiliary Drive Group | 1 |
| 1L***66 | Generator Group | 1 |
| 1L***67 | Generator Arrangement | 1 |
1l8971 Generator Arrangement--12 Volt, 40 Ampere
| 1L***54 | Auxiliary Drive Group | 1 |
| 1L***70 | Generator Group | 1 |
| 1L***71 | Generator Arrangement | 1 |
1l8965 Generator Arrangement--6 Volt, 40 Ampere
| 1L***54 | Auxiliary Drive Group | 1 |
| 1L***56 | Generator Group | 1 |
| 1L***65 | Generator Arrangement | 1 |
1l8969 Generator Arrangement--12 Volt, 10 Ampere
| 1L***54 | Auxiliary Drive Group | 1 |
| 1L***68 | Generator Group | 1 |
| 1L***69 | Generator Arrangement | 1 |
1l8973 Generator Arrangement--32 Volt, 15 Ampere
| 1L***54 | Auxiliary Drive Group | 1 |
| 1L***72 | Generator Group | 1 |
| 1L***73 | Generator Arrangement | 1 |
2m6664 Generator Assembly--6 Volt, 40 Ampere--Replaces 8h1963
| 2M***64 | Generator Assembly | 1 |
1l8956 Generator Group--6 Volt, 40 Ampere--Type 5
| 1L***56 | Generator Group | 1 |
1l8956 Generator Group--6 Volt, 40 Ampere--Type 1
| 1L***56 | Generator Group | 1 |
1l8956 Generator Group--6 Volt, 40 Ampere--Type 4
| 1L***56 | Generator Group | 1 |
1l8970 Generator Group--12 Volt, 40 Ampere--Type 2
| 1L***70 | Generator Group | 1 |
1l8956 Generator Group--6 Volt, 40 Ampere--Type 3
| 1L***56 | Generator Group | 1 |
1l8970 Generator Group--12 Volt, 40 Ampere--Type 3
| 1L***70 | Generator Group | 1 |
1l8956 Generator Group--6 Volt, 40 Ampere--Type 2
| 1L***56 | Generator Group | 1 |
1l8972 Generator Group--32 Volt, 15 Ampere
| 1L***72 | Generator Group | 1 |
1l8970 Generator Group--12 Volt, 40 Ampere--Type 1
| 1L***70 | Generator Group | 1 |
1l8956 Generator Group--6 Volt, 40 Ampere--Type 6
| 1L***56 | Generator Group | 1 |
1l8966 Generator Group--6 Volt, 18 Ampere--Type 2
| 1L***66 | Generator Group | 1 |
1l8968 Generator Group--12 Volt, 10 Ampere--Type 1
| 1L***68 | Generator Group | 1 |
1l8968 Generator Group--12 Volt, 10 Ampere--Type 2
| 1L***68 | Generator Group | 1 |
1l8966 Generator Group--6 Volt, 18 Ampere
| 1L***66 | Generator Group | 1 |
2l151 Glow Plug Arrangement--110 Volt
| 2H***33 | Transformer | 1 |
| 2L***50 | Glow Plug Group | 1 |
| 2L***51 | Glow Plug Arrangement | 1 |
2l150 Glow Plug Group--24 Volt--Type 2
| 2L***50 | Glow Plug Group | 1 |
2l150 Glow Plug Group--24 Volt
| 2L***50 | Glow Plug Group | 1 |
2l148 Glow Plug Group--24 Volt--Type 2
| 2L***48 | Glow Plug Group | 1 |
2l149 Glow Plug Group--32 Volt
| 2L***49 | Glow Plug Group | 1 |
2l148 Glow Plug Group--24 Volt--Type 1
| 2L***48 | Glow Plug Group | 1 |
2h2834 Governor Assembly
| 2H***34 | Governor Assembly | 1 |
3l2750 Governor Control Group--Single Cable--L.H.--Type 1--Replaces 3l2741
| 3L***50 | Governor Control Group; Governor Single Cable Control Group | 1 |
7f6899 Governor Control Group--Pilot House Mounted
| 7F***99 | Governor Control Group | 1 |
3l2750 Control Group--Positive Locking--L.H.--Type 2
| 3L***50 | Governor Control Group; Governor Single Cable Control Group | 1 |
3l6934 Governor Conversion Group--10% Regulation At 1600 To 1900 R.P.M.
| 3L***34 | Governor Conversion Group | 1 |
2l187 Governor Group--Type 2
| 2L***87 | Governor Group | 1 |
2l187 Governor Group--Type 1
| 2L***87 | Governor Group | 1 |
2l6745 Governor Pneumatic Actuator Group--Type 2
| 2L***45 | Governor Pneumatic Actuator Group | 1 |
1l2807 Governor Actuator Group--Type 1
| 1L***07 | Governor Pneumatic Actuator Group | 1 |
1l2807 Governor Actuator Group--Type 2
| 1L***07 | Governor Pneumatic Actuator Group | 1 |
2l6745 Governor Pneumatic Actuator Group--Type 1
| 2L***45 | Governor Pneumatic Actuator Group | 1 |
1l9152 Governor Remote Control Group--L.H.
| 0S***85 | Bolt; 12.7 mm (1/2") Diameter X 38.1 mm (1 1/2") Length Generator To Engine | 2 |
| 1L***58 | Remote Governor Control Group; Governor Remote Control Group | 1 |
| 1L***51 | Bracket Assembly--Cross Shaft | 1 |
1l9154 Governor Remote Control Group--Single Cable--L.H.
| 1L***52 | Governor Remote Control Group | 1 |
| 1L***54 | Governor Remote Control Group | 1 |
| 3H***16 | Spring--Control Shaft Return | 1 |
3l2741 Governor Remote Control Group--L.H.
| 2L***45 | Lever--Quadrant Assembly | 1 |
| 2L***49 | Quadrant Assembly--Control Handle To Shaft | 1 |
| 3L***82 | Positive Locking Control Group | 1 |
1l8759 Governor Remote Control Group--Single Cable--R.H.
| 1L***78 | Spring--Control Shaft Return | 1 |
| 1L***57 | Remote Governor Control Group; Governor Remote Control Group | 1 |
| 1L***59 | Governor Remote Control Group; Single Cable Governor Remote Control Group | 1 |
1l8760 Governor Remote Control Group--Single Cable--L.H.
| 1L***58 | Remote Governor Control Group; Governor Remote Control Group | 1 |
| 1L***60 | Governor Remote Control Group | 1 |
| 3H***16 | Spring--Control Shaft Return | 1 |
3l2112 Governor Single Cable Control Group--R.H.
| 0S***92 | Bolt Cover Assembly To Governor | 2 |
| 1A***02 | Spring--Lever To Bracket | 1 |
| 2L***93 | Positive Locking Control Group | 1 |
Heat Exchanger Assembly
3l8881 Ignition System Group
| 3L***81 | Ignition System Group | 1 |
2l189 Ignition System Group
| 2L***89 | Ignition System Group | 1 |
2l251 Instrument Panel Group--Pilot House Mounted
| 2L***51 | Instrument Panel Group | 1 |
4l1687 Instrument Panel Group--Replaces 1l6596
| 4L***87 | Instrument Panel Group | 1 |
1l6596 Instrument Panel Group--Pilot House Mounted
| 1L***96 | Instrument Panel Group | 1 |
2l5349 Instrument Panel Group--R.H.--Type 2
| 2L***49 | Instrument Panel Group; Instrument Panel Group R.H. | 1 |
2l5349 Instrument Panel Group--R.H.--Replaces 1l9047--Type 1
| 2L***49 | Instrument Panel Group; Instrument Panel Group R.H. | 1 |
1l9047 Instrument Panel Group
| 1L***47 | Instrument Panel Group | 1 |
1l9084 Instrument Panel Group
| 1L***84 | Instrument Panel Group | 1 |
1l9230 Junction Box Group
| 1L***30 | Junction Box Group | 1 |
5f7739 Magnetic Switch
| 5F***39 | Magnetic Switch | 1 |
8f5871 Magneto
| 8F***71 | Magneto | 1 |
5m6374 Magneto Assembly--Replaces 9h6374
| 5M***74 | Magneto Assembly | 1 |
5m2850 Magneto Assembly--Replaces 5m6374
| 5M***50 | Magneto Assembly | 1 |
9h6374 Magneto Assembly
| 9H***74 | Magneto Assembly | 1 |
7h6866 Magneto Assembly
| 7H***66 | Magneto Assembly | 1 |
9h4480 Magneto Assembly
| 9H***80 | Magneto Assembly | 1 |
2l7222 Manifold, Carburetor And Air Cleaner Group
| 2L***22 | Manifold Carburetor And Air Cleaner Group; Manifold, Carburetor And Air Cleaner Group | 1 |
2l196 Manifold, Carburetor And Breather Group
| 2L***96 | Manifold Carburetor And Breather Group; Manifold, Carburetor And Breather Group | 1 |
3l8887 Manifold, Carburetor And Flame Arrester Group
| 3L***87 | Manifold Carburetor And Flame Arrester Group; Manifold, Carburetor And Flame Arrester Group | 1 |
3l2392 Motor--6 Volt
2l770 Muffler Group--Spark Arresting Type
| 2L***70 | Muffler Group | 1 |
2l585 Oil Cooler Group
| 2L***85 | Oil Cooler Group | 1 |
6h9937 Oil Filter Field Changeover Group
| 6H***37 | Oil Filter Field Changeover Group | 1 |
2l7258 Oil Lines Group
| 2L***58 | Oil Line Group | 1 |
2l7258 Oil Line Group
| 2L***58 | Oil Line Group | 1 |
3l8880 Oil Line Group--Type 2
| 3L***80 | Oil Lines Group | 1 |
3l8880 Oil Lines Group
| 3L***80 | Oil Lines Group | 1 |
2h7664 Oil Pump Assembly
| 2H***64 | Oil Pump Assembly | 1 |
1l9505 Positive Locking Control And Panel Arrangement--R.H.
| 1L***55 | Control Group; Positive Locking Control Group | 1 |
| 1L***47 | Instrument Panel Group | 1 |
| 1L***05 | Positive Locking Control And Panel Arrangement | 1 |
1l9508 Positive Locking Control And Panel Arrangement--L.H.
| 1L***84 | Instrument Panel Group | 1 |
| 1L***50 | Positive Locking Control Group | 1 |
| 1L***08 | Positive Locking Control And Panel Arrangement | 1 |
1l9506 Positive Locking Control And Panel Arrangement--L.H.--
| 1L***56 | Positive Locking Control Group | 1 |
| 1L***84 | Instrument Panel Group | 1 |
| 1L***06 | Positive Locking Control And Panel Arrangement--L.H. | 1 |
3l2682 Positive Locking Control Group--L.H.--Type 2
| 3L***82 | Positive Locking Control Group | 1 |
1l8756 Control Group--Positive Locking--R.H.--Type 2
| 1L***56 | Positive Locking Control Group | 1 |
2l8993 Positive Locking Control Group--L.H.--Type 1
| 2L***93 | Positive Locking Control Group | 1 |
1l9150 Positive Locking Control Group--L.H.
| 0S***85 | Bolt; 12.7 mm (1/2") Diameter X 38.1 mm (1 1/2") Length Generator To Engine | 2 |
| 1L***56 | Positive Locking Control Group | 1 |
| 1L***50 | Positive Locking Control Group | 1 |
1l8756 Control Group--Positive Locking--L.H.--Type 3
| 1L***56 | Positive Locking Control Group | 1 |
1l8756 Positive Locking Control Group--Type 1
| 1L***56 | Positive Locking Control Group | 1 |
3l2682 Positive Locking Control Group--Type 1
| 3L***82 | Positive Locking Control Group | 1 |
2l8993 Governor Control Group--Positive Locking--L.H.--Type 2
| 2L***93 | Positive Locking Control Group | 1 |
8f2184 Pump
3h3512 Pump Assembly
| 3H***12 | Pump Assembly | 1 |
2l2252 Raw Water Pump And Lines Arrangement
| 1L***53 | Raw Water Pump Group | 1 |
| 2L***89 | Water Lines Group; Raw Water Lines Group | 1 |
| 2L***52 | Raw Water Pump And Lines Arrangement | 1 |
2l9964 Raw Water Pump And Lines Arrangement
| 2L***89 | Water Lines Group; Raw Water Lines Group | 1 |
| 2L***64 | Raw Water Pump And Lines Arrangement | 1 |
| 2L***65 | Raw Water Pump Group | 1 |
1l8553 Raw Water Pump Group--Type 1
| 1L***53 | Raw Water Pump Group | 1 |
2l9965 Raw Water Pump Group--Rubber Impeller
| 2L***65 | Raw Water Pump Group | 1 |
1l8553 Raw Water Pump Group--Type 2
| 1L***53 | Raw Water Pump Group | 1 |
7h4150 Regulator--6 Volt, 40 Ampere--Replaces 6h9206
| 7H***50 | Regulator | 1 |
6f9464 Regulator--12 Volt, 40 Ampere
| 6F***64 | Regulator | 1 |
7f4702 Regulator--6 Volt, 40 Ampere
| 7F***02 | Regulator | 1 |
1l3468 Regulator--6 Volt, 18 Ampere
| 1L***68 | Regulator | 1 |
4f148 Regulator--12 Volt, 10 Ampere
| 4F***48 | Regulator | 1 |
7h842 Regulator--6 Volt, 18 Ampere
| 7H***42 | Regulator | 1 |
6h9206 Regulator--6 Volt, 40 Ampere--Replaces 7f4702
| 6H***06 | Regulator | 1 |
1l3467 Regulator--12 Volt, 40 Ampere
| 1L***67 | Regulator | 1 |
3h2273 Regulator--32 Volt, 15 Ampere
| 3H***73 | Regulator | 1 |
1m2381 Regulator Assembly--6 Volt, 18 Ampere--Replaces 7h842
| 1M***81 | Regulator Assembly | 1 |
7m3962 Regulator Assembly--6 Volt, 20 Ampere--Replaces 1m2381
| 7M***62 | Regulator Assembly | 1 |
9h6316 Regulator Assembly--6 Volt, 40 Ampere--Replaces 7h4150
| 9H***16 | Regulator Assembly | 1 |
Relay And Element Assemblies
1l9509 Remote Control And Panel Arrangement--R.H.
| 1L***57 | Remote Governor Control Group; Governor Remote Control Group | 1 |
| 1L***47 | Instrument Panel Group | 1 |
| 1L***09 | Remote Control And Panel Arrangement | 1 |
1l9512 Remote Control And Panel Arrangement--L.H.
| 1L***84 | Instrument Panel Group | 1 |
| 1L***52 | Governor Remote Control Group | 1 |
| 1L***12 | Remote Control And Panel Arrangement | 1 |
2l9292 Remote Governor Control Group--L.H.
| 2L***92 | Remote Governor Control Group | 1 |
1l8757 Remote Governor Control Group
| 1L***57 | Remote Governor Control Group; Governor Remote Control Group | 1 |
1l8758 Remote Governor Control Group
| 1L***58 | Remote Governor Control Group; Governor Remote Control Group | 1 |
1l9875 Safety Alarm Group--Type 1
| 1L***75 | Safety Alarm Group | 1 |
1l9875 Safety Alarm Group--Type 2
| 1L***75 | Safety Alarm Group | 1 |
2l220 Safety Drip Collector Group
| 2L***20 | Safety Drip Collector Group | 1 |
3l8876 Safety Drip Collector Group
| 3L***76 | Safety Drip Collector Group | 1 |
3l7758 Safety Shut-Off And Reset, Service Meter And Tachometer Drive Group--Part 1 Of 2
| 3L***58 | Safety Shut-Off And Reset, Service Meter And Tachometer Drive Group | 1 |
3l7758 Safety Shut-Off And Reset, Service Meter And Tachometer Drive Group--Part 2 Of 2
| 3L***58 | Safety Shut-Off And Reset, Service Meter And Tachometer Drive Group | 1 |
7m5996 Separate Lubrication Conversion Group--Field Installation
| 7M***96 | Separate Lubrication Conversion Group | 1 |
1l9516 Single Cable Control And Panel Arrangement--L.H.
| 1L***84 | Instrument Panel Group | 1 |
| 1L***54 | Governor Remote Control Group | 1 |
| 1L***16 | Single Cable Control And Panel Arrangement | 1 |
1l9514 Single Cable Control And Panel Arrangement--
| 1L***60 | Governor Remote Control Group | 1 |
| 1L***84 | Instrument Panel Group | 1 |
| 1L***14 | Single Cable Control And Panel Arrangement | 1 |
1l9513 Single Cable Control And Panel Arrangement--R.H.
| 1L***59 | Governor Remote Control Group; Single Cable Governor Remote Control Group | 1 |
| 1L***47 | Instrument Panel Group | 1 |
| 1L***13 | Single Cable Control And Panel Arrangement | 1 |
2l194 Starter Pinion Group
| 2L***94 | Starter Pinion Group | 1 |
8f2743 Starting Crank Group
| 8F***43 | Starting Crank Group; Manual Starting Crank Group | 1 |
2l222 Starting Engine Arrangement
| 0S***92 | Bolt--Cover To Flywheel Housing | 3 |
| 2B***57 | Plug (.375" Pipe Thread) | 1 |
| 2H***61 | Fuel System Group | 1 |
3l8916 Starting Engine Arrangement
| 0S***92 | Bolt--Cover To Flywheel Housing | 3 |
| 2B***57 | Plug (.375" Pipe Thread) | 1 |
| 2H***61 | Fuel System Group | 1 |
8f4185 Foot Valve And Strainer Assembly
| 8F***85 | Strainer As; Foot Valve And Strainer Assembly | 1 |
3f1006 Switch
| 3F***06 | Switch; (Elec. Horn) | 1 |
4h5122 Tachometer Drive Group
| 4H***22 | Tachometer Drive Group | 1 |
3l3610 Tachometer Drive Group
| 3L***10 | Tachometer Drive Group | 1 |
1l5010 Air Receiver Group
| 1L***10 | Tank Group-Air | 1 |
2l55 Thermometer Group
| 2L***55 | Thermometer Group | 1 |
1l5011 Regulator And Pressure Reducing Valve
| 1L***11 | Valve Group-Starting Air | 1 |
2l7339 Water Cooled Exhaust Manifold Group--Field Changeover
| 2L***39 | Water Cooled Exhaust Manifold Group | 1 |
2l989 Water Lines Group
| 2L***89 | Water Lines Group; Raw Water Lines Group | 1 |
5h7095 Water Lines Group
| 5H***95 | Water Lines Group | 1 |
3l9921 Whistle Valve
| 3L***21 | Whistle Valve Assembly | 1 |
Diesel Engine
2l3014 Basic Governor Group--Part 2 Of 2--Field Installation
| 2L***14 | Basic Governor Group | 1 |
2l3014 Basic Governor Group--Part 2 Of 2
| 2L***14 | Basic Governor Group | 1 |
2l3014 Basic Governor Group--Part 1 Of 2
| 2L***14 | Basic Governor Group | 1 |
2l3014 Basic Governor Group--Part 1 Of 2--Field Installation
| 2L***14 | Basic Governor Group | 1 |
6h3185 Breather Group
| 6H***85 | Breather Group | 1 |
5h8098 Camshaft And Auxiliary Idler Gear Group
| 5H***98 | Camshaft And Auxiliary Idler Gear Group | 1 |
5h5874 Camshaft Group
| 5H***74 | Camshaft Group | 1 |
5h5874 Camshaft
2l3057 Complete Governor Group--10 Percent Regulation At 1600 R.P.M.
| 2L***57 | Complete Governor Group | 1 |
4h5448 Connecting Rod And Piston Group--6 Required
| 4H***48 | Connecting Rod And Piston Group | 1 |
2m5570 Connecting Rod And Piston Group--6 Required
| 2M***70 | Connecting Rod And Piston Group | 1 |
Crankshaft And Damper
Crankshaft Bearing Replacement Groups
Cylinder Block And Covers--Side View--Part 1 Of 2
Cylinder Block And Covers--Rear View--Part 2 Of 2
5h8056 Cylinder Block And Covers Group--Rear View--Part 2 Of 2
| 5H***56 | Cylinder Block And Covers Group | 1 |
5h8056 Cylinder Block And Covers Group--Side View--Part 1 Of 2
| 5H***56 | Cylinder Block And Covers Group | 1 |
6h5795 Cylinder Block Assembly
| 6H***95 | Cylinder Block Assembly | 1 |
5h1480 Cylinder Block Assembly
| 5H***80 | Cylinder Block Assembly | 1 |
1m764 Cylinder Block Assembly
| 1M***64 | Cylinder Block Assembly | 1 |
Cylinder Head And Valve Mechanism--Side View--Part 1 Of 2
Cylinder Head And Valve Mechanism--End View--Part 2 Of 2
5h8055 Cylinder Head And Valve Mechanism Group--End View--Part 2 Of 2
| 5H***55 | Cylinder Head And Valve Mechanism Group | 1 |
5h8055 Cylinder Head And Valve Mechanism Group--Side View--Part 1 Of 2
| 5H***55 | Cylinder Head And Valve Mechanism Group | 1 |
3l5182 Damper Guard Group
| 3L***82 | Damper Guard Group | 1 |
1l7914 Engine Support
| 1L***14 | Engine Support Group | 1 |
1l7914 Engine Support Group
| 1L***14 | Engine Support Group | 1 |
Flywheel
1l7900 Fuel Filter Group
| 1L***00 | Fuel Filter Group | 1 |
Fuel Injection Valves And Lines
5h9564 Fuel Pump And Accessory Drive Housing Group
| 5H***64 | Fuel Pump And Accessory Drive Housing Group | 1 |
Fuel Pump Housing
4h8853 Fuel Pump Housing Group
| 4H***53 | Fuel Pump Housing Group | 1 |
5h7086 Fuel Transfer Pump Assembly
| 5H***86 | Fuel Transfer Pump Assembly | 1 |
3l7339 Governor Group--Part 2 Of 2
| 3L***39 | Governor Group | 1 |
3l7339 Governor Group--Part 1 Of 2
| 3L***39 | Governor Group | 1 |
2l3059 Governor Group--10% Regulation At 1500 R.P.M.
| 2L***59 | Governor Group | 1 |
6h6603 Hour Meter And Tachometer Drive Group
| 6H***03 | Hour Meter And Tachometer Drive Group | 1 |
5h8058 Hour Meter Group
| 5H***58 | Hour Meter Group | 1 |
Jacket Water Pump And Drive
Manifolds
1l7902 Oil Cooler Group
| 1L***02 | Oil Cooler Group | 1 |
Oil Filter
5h5795 Oil Filter Group
| 5H***95 | Oil Filter Group | 1 |
Oil Lines
Oil Pan
2l700 Oil Pan Group
| 2L***00 | Oil Pan Group | 1 |
2m8671 Oil Pump Assembly
| 2M***71 | Oil Pump Assembly | 1 |
5h7281 Oil Pump Assembly
| 5H***81 | Oil Pump Assembly | 1 |
8h5257 Service Meter And Tachometer Drive Group
| 8H***57 | Service Meter And Tachometer Drive Group | 1 |
8h5252 Service Meter Group
| 8H***52 | Service Meter Group | 1 |
Silencer
1l7896 Silencer Group
| 1L***96 | Silencer Group | 1 |
3l7812 Sump Pump Assembly
| 3L***12 | Sump Pump Assembly | 1 |
2l760 Sump Pump Assembly
| 2L***60 | Sump Pump Assembly | 1 |
1l9172 Sump Pump Group--R.H. Or L.H. Mounted
| 1L***72 | Sump Pump Group | 1 |
3l7814 Sump Pump Group
| 3L***14 | Sump Pump Group | 1 |
1l7916 Surge Tank And Water Lines Group--Part 1 Of 2
| 1L***16 | Surge Tank And Water Lines Group | 1 |
1l7916 Surge Tank And Water Lines Group--Part 2 Of 2
| 1L***16 | Surge Tank And Water Lines Group | 1 |
4h5122 Tachometer Drive Group
| 4H***22 | Tachometer Drive Group | 1 |
Marine Gears
2l1952 Connections And Mounting Group--Type 1
| 2L***52 | Connections And Mounting Group | 1 |
2l1952 Connection And Mounting Group--Type 2
| 2L***52 | Connections And Mounting Group | 1 |
2l1083 Connections And Mounting Group--Type 1
| 2L***83 | Connections And Mounting Group | 1 |
2l1953 Connections And Mounting Group--Type 2
| 2L***53 | Connections And Mounting Group | 1 |
2l1083 Connections And Mounting Group--Type 2
| 2L***83 | Connections And Mounting Group | 1 |
1l9683 Connections And Mounting Group
| 1L***83 | Connections And Mounting Group | 1 |
2l1953 Connections And Mounting Group--Type 1
| 2L***53 | Connections And Mounting Group | 1 |
8f9866 Grease Gun
| 8F***66 | Grease Gun As | 1 |
Name Plates And Transfers
| 1F***58 | Plate-- Engine Information | 1 |
| 1H***63 | Plate Serial Number | 1 |
| 1H***44 | Transfer--Oil Filter Instructions--1 7/8" High | 1 |
2l1955 Reverse And Reduction Gear Arrangement--3 : 1 Ratio
| 1L***31 | Reverse And Reduction Gear Assembly | 1 |
| 2L***52 | Connections And Mounting Group | 1 |
| 2L***55 | Reverse And Reduction Gear Arrangement | 1 |
1l9684 Reverse And Reduction Gear Arrangement--2 : 1 Ratio
| 1L***32 | Reverse And Reduction Gear Assembly | 1 |
| 1L***83 | Connections And Mounting Group | 1 |
| 1L***84 | Reverse And Reduction Gear Arrangement | 1 |
2l1956 Reverse And Reduction Gear Arrangement--4.4 : 1 Ratio
| 1L***30 | Reverse And Reduction Gear Assembly | 1 |
| 2L***53 | Connections And Mounting Group | 1 |
| 2L***56 | Reverse And Reduction Gear Arrangement | 1 |
2l1954 Reverse And Reduction Gear Arrangement--2 : 1 Ratio
| 1L***32 | Reverse And Reduction Gear Assembly | 1 |
| 2L***52 | Connections And Mounting Group | 1 |
| 2L***54 | Reverse And Reduction Gear Arrangement | 1 |
1l9686 Reverse And Reduction Gear Arrangement--4.4 : 1 Ratio
| 1L***30 | Reverse And Reduction Gear Assembly | 1 |
| 1L***86 | Reverse And Reduction Gear Arrangement | 1 |
| 2L***83 | Connections And Mounting Group | 1 |
1l9685 Reverse And Reduction Gear Arrangement--3 : 1 Ratio
| 1L***31 | Reverse And Reduction Gear Assembly | 1 |
| 1L***83 | Connections And Mounting Group | 1 |
| 1L***85 | Reverse And Reduction Gear Arrangement | 1 |
1l7931 Reverse And Reduction Gear Assembly (3.00 : 1 Ratio)--Side View--Part 2 Of 2
| 1L***31 | Reverse And Reduction Gear Assembly | 1 |
1l7932 Reverse And Reduction Gear Assembly (1.96 : 1 Ratio)--Rear View--Part 1 Of 2
| 1L***32 | Reverse And Reduction Gear Assembly | 1 |
1l7930 Reverse And Reduction Gear Assembly (4.38 : 1 Ratio)--Rear View--Part 1 Of 2
| 1L***30 | Reverse And Reduction Gear Assembly | 1 |
1l7931 Reverse And Reduction Gear Assembly (3.00 : 1 Ratio)--Rear View--Part 1 Of 2
| 1L***31 | Reverse And Reduction Gear Assembly | 1 |
1l7930 Reverse And Reduction Gear Assembly (4.38 : 1 Ratio)--Side View--Part 2 Of 2
| 1L***30 | Reverse And Reduction Gear Assembly | 1 |
1l7932 Reverse And Reduction Gear Assembly (1.96 : 1 Ratio)--Side View--Part 2 Of 2
| 1L***32 | Reverse And Reduction Gear Assembly | 1 |
6h9908 Tool Group
| 6H***08 | Tool Group | 1 |
4l1560 Tool Group--Replaced By 9s7977
| 4L***60 | Tool Group | 1 |
9s7977 Hand Tool Group
| 9S***77 | Tool Group-Hand | 1 |
D326F serial number reference
On these mechanical-era Cat marine engines the ID plate is a stamped metal tag riveted to the engine block or timing gear housing, often near the flywheel housing or fuel injection pump side. The first three characters of the serial number are the prefix and identify the specific engine model/series; the digits that follow are the sequential build number for that unit. Always read the prefix straight off the plate rather than assuming it from the engine casting number.
| Prefix | Identifies | Notes |
|---|---|---|
| 40B | D326F marine engine | Only serial-number prefix documented for the D326F marine engine. Cat marine-engine prefix references tie 40B directly to the D326F designation. The same 40B series also shows up on catalog listings for the closely related base D326 diesel engine, consistent with the marine and non-marine catalog entries sharing one engine family and one prefix. No separate prefix found for a turbocharged or generator-drive variant. Confirm any internal running-change break points within this prefix with your dealer. |
Frequently asked questions
What engine does the Caterpillar D326F use?
The D326F is itself a Caterpillar diesel engine, not a machine that houses one. It is a mechanical, naturally aspirated inline 6-cylinder marine diesel from Cat's D318/D320/D326 family, identified by serial prefixes 39B1-up and 40B1-up. It predates electronic engine controls and carries no ECM or fault-code system.
What is the operating weight of the Caterpillar D326F?
Caterpillar has not published a dry or operating weight for the D326F in accessible factory literature. As a fixed marine propulsion or auxiliary engine rather than a mobile machine, it does not carry an operating-weight spec the way a machine does; treat any weight figure found elsewhere as unverified until confirmed against the engine's own OMM or a dealer record.
What replaced the Caterpillar D326F?
No documented predecessor or successor is confirmed for the D326F specifically. It shares service, parts, and reduction-gear documentation with its Roots-blown sibling, the D337, within the broader D330/D333/D334/D336/D337 mechanical engine family, but no source ties a direct model-for-model replacement to the D326F.
What D326F owners discuss
What do owners and mechanics actually say about the D326F online?
Not much, and what exists is thin. Dedicated threads naming the D326F specifically are rare. Most discussion of this engine generation gets folded into broader talk about the mechanical Cat inline-six family it belongs to, since the D318, D320, D326 and D337 were documented together in the same era of factory service literature. The consensus that does surface: a simple, all-mechanical precombustion-chamber diesel with no electronics to chase, dependable if it was maintained on schedule, but old enough now that finding someone who has personally wrenched on one is uncommon.
What wear patterns show up on an engine this old and this mechanical?
The pattern is the same one reported across this whole Cat mechanical-diesel generation: injector nozzle spray degradation and carbon buildup from decades of duty cycles, cylinder liner and ring wear that shows up as rising oil consumption and blue smoke under load, valve guide and seat wear, and injection pump plunger wear that shows up as harder starting and rougher idle over time. None of this is unique to the D326F, it is simply what a precombustion-chamber mechanical diesel does after 40-plus years of service, especially if it sat unused for long stretches between owners.
Are there known quirks with how this engine starts and runs?
Yes, and they are quirks of the whole design generation rather than a D326F-specific defect. It is a precombustion-chamber (indirect injection) engine, so cold starts lean on glow-assist or an ether-assist habit more than a direct-injection engine would, and starting hardware on marine and industrial installs of this vintage ranges from hand crank to pony motor to straight electric start depending on how the unit was originally configured. There is no ECM and no fault code list, so all diagnosis is mechanical: compression check, injector pop-test, and static timing verification rather than a scan tool.
What's the biggest practical headache owners report?
Parts. A search for injector pumps and nozzles for this specific engine turns up owners actively hunting for exactly those parts, with no easy new-old-stock source. The practical path reported by people working on this family is to go through vintage industrial-diesel rebuilders who still service the precombustion-chamber Cat sixes, cross-reference against the original servicemen's reference manual for the 4-1/2 to 5-3/4 inch bore family, and plan on rebuilding original components rather than finding replacements on a shelf.
What should I know about the marine cooling setup before buying?
Marine installs of this generation ran raw-water or heat-exchanger cooling rather than the fan-and-radiator setup used on industrial/genset versions of the same basic engine. That means anode maintenance and raw-water side inspection matter more here than on a land engine, and any hull or keel-cooling piping tied to the install should be checked for corrosion history along with the engine itself. Specific cooling hardware varies by how the individual boat builder integrated the engine, so treat this as install-dependent rather than a fixed factory configuration.
What should I check before buying a used D326F?
Do a compression test across all cylinders and compare them to each other rather than to a published spec, since exact figures for this engine are not well documented. Pull the oil and look for coolant contamination and metal in the pan. Check the injector pump for smooth, even fuel delivery and inspect nozzles for spray pattern. Look hard at the raw-water side of the cooling system for corrosion or salt scale if it is a marine-cooled unit, and confirm the reduction gear turns freely and doesn't weep gear oil. Ask for any service paperwork, since hour meters on engines this old are frequently disconnected or unreliable and documented history is worth more than an odometer-style number. Have your dealer or a qualified marine diesel mechanic verify compression, injection timing, and cooling system integrity before you commit to a purchase or put the engine back into service.
Is there anything notable about this engine's design beyond being a workhorse?
One detail that surfaces in industry literature rather than owner forums: the combustion chamber design used in this Cat engine family was significant enough that it became the starting point for a long-running single-cylinder lubricant test engine used across the diesel industry to evaluate engine oils. That lineage says more about the soundness of the precombustion-chamber design than it does about any specific D326F unit still in service, but it explains why this engine generation shows up in technical literature even where owner chatter is scarce.
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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