Caterpillar 1676
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar 1676 is not a complete machine - it is a bare V8 diesel engine built for the Class 8 on-highway truck market, sold to independent truck manufacturers such as Kenworth, Oshkosh, and Atkinson for their own chassis. It displaces 11.5 L (700 cu in) from a 114 mm x 140 mm (4.5 in x 5.5 in) bore and stroke, with a double-overhead-cam valve train driven by separate front and rear timing gear trains, four valves per cylinder, turbocharging and aftercooling, and precombustion-chamber fuel injection. Factory output is rated at roughly 340 hp, though period sources also cite a lower 320 hp figure depending on configuration. Caterpillar built the 1676 from late 1965 to about 1967 under serial prefix 54B. It followed the smaller-bore six-cylinder 1673 in Cat's truck-engine line and was itself replaced by the six-cylinder 1693, later renamed 3406. Configuration choices centered on driveline fitment for the truck builder - flywheel-housing and PTO-mounting options and charging-system voltage to match the installer's electrical system - rather than the body or undercarriage options a complete machine would offer.
The 1676 saw no distinct sub-series or model-year generations; it was a single design fielded for roughly two years before Caterpillar moved its truck-engine line to the simpler six-cylinder 1693. Its double-overhead-cam, dual-gear-train architecture proved complex next to that six-cylinder, but the layout carried forward directly into Caterpillar's later 18-liter 3408 V8, which used the 1676 as its design basis. In today's used and parts market the 1676 is a scarce, collectible engine rather than a working fleet unit - most surviving examples sit in restored vintage Kenworth, Oshkosh, and Atkinson trucks. Caterpillar's dealer parts network no longer stocks this engine, so parts support runs through vintage-diesel rebuilders, salvage engines pulled from period trucks, and machinists who reproduce wear items, making documented factory service data and originality of surviving parts the main value drivers for buyers.
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 1676 specifications
Engine
| Model / generation | Cat 1676 truck engine, factory serial number prefix 54B. Introduced late 1965 as an all-new design; superseded around 1967 by the six-cylinder 1693 (later renamed 3406). Also formed the design basis for Cat's later 3408 V-8. |
| Configuration | V-8, double overhead camshaft, front and rear timing gear train, pre-combustion chamber (pre-cup) fuel injectors |
| Rated power | 340 hp (254 kW) at introduction — factory launch rating; treat as approximate, exact governed rpm not documented |
| Displacement | 11.5 L (700 cu in) |
| Bore x stroke | 114 mm x 140 mm (4.5 in x 5.5 in) |
| Cylinders | 8, V-configuration |
| Aspiration | Turbocharged with aftercooling (charge-air cooled) |
| Valvetrain | 4 valves per cylinder |
| Emissions tier | Not applicable — pre-dates emissions certification standards (engine dates to 1965) |
Weights
| Operating / shipping weight | Not documented in available sources for this engine |
Dimensions
| Overall dimensions | Not documented in available sources for this engine |
Performance
| Governed speed / torque | Not documented in available sources for this engine |
| Class-relevant performance figures | Not applicable — bare engine model, not a complete machine, so travel speed, drawbar, and gradeability figures do not apply |
Service capacities (summary)
| Fuel tank | Not applicable to a bare engine model — tank is truck-specific |
| Hydraulic system | Not applicable — no integral hydraulic system on this engine |
| Engine oil | Not documented in available sources for this engine |
| Cooling system | Not documented in available sources for this engine |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
1676 fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase, with oil filter (Cat 1676 V8 truck engine, engine prefix 54B) | Exact factory fill volume not confirmed from sources located. Not stated in any publicly accessible technical listing found for this specific build; treat any single-source figure (e.g. an internet-forum claim of roughly 11 L) as unverified until checked against original factory literature. | Original branded recommendation not confirmed. The 1676 (introduced late 1965, discontinued circa 1967) predates Caterpillar's modern branded fluid line - Cat DEO, TDTO, ELC and HYDO all post-date this engine by decades. Period factory guidance would have called out a diesel engine oil of the API/Caterpillar engine-oil specification current for 1965-67, graded by ambient temperature, rather than any of today's named Cat products. Confirm exact grade and brand against the original engine operator/service literature for prefix 54B. |
| Cooling system (engine-side circuit) | Not documented in sources located. The 1676 was sold as a standalone engine to Class 8 truck builders; total system capacity (radiator, hoses, tank) was set by the truck chassis builder, not by Caterpillar, and varies by installation. | Not confirmed by name for this engine. Period Caterpillar guidance of that era called for a quality low-silicate ethylene-glycol antifreeze/water mixture with a Caterpillar-approved supplemental coolant additive (SCA); this predates Cat Extended Life Coolant (ELC), introduced decades later. Verify against original literature. |
| Fuel tank | Not applicable to Caterpillar engine documentation. Fuel tank was part of the truck body/chassis, sized and supplied by the truck manufacturer, not Caterpillar. | N/A - not part of Caterpillar engine literature for this product. |
| Transmission, final drive, hydraulic system/tank, axles/differentials | Not applicable. The 1676 was sold only as a standalone V8 diesel engine for installation by Class 8 on-highway truck builders of the mid-to-late 1960s. Caterpillar did not supply or publish specifications for the transmission, final drive, hydraulic system, or axles in these truck installations. | N/A - these systems and their fluid specs belong to the truck chassis/driveline manufacturer, not to Caterpillar engine literature. |
| Grease (chassis/engine-mounted grease points, spec only) | N/A (grease spec only, no fill volume applicable) | Not confirmed for this specific engine from sources located. No period-correct grease specification tied explicitly to the 1676 was found; do not assume a modern Cat grease name applies to 1960s factory literature without checking the original manual. |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar 1676 maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 50 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 6,000 h |
|
Servicing the 1676 beyond the schedule
Predictive Maintenance & Fluid Analysis
The 1676 predates hour-meter diagnostics and oil sampling programs, so predictive care means trained observation. Watch exhaust color at startup and under load: white smoke points to worn precombustion chambers or injectors, black smoke to a fouled turbocharger or overfueling. Check crankcase blow-by and oil condition for early ring or liner wear. Listen at the front and rear timing-gear covers for whine or rattle signaling gear-train backlash growth. Check coolant for aftercooler-core scaling, since deposits there quietly rob charge-air cooling and boost efficiency long before power loss is obvious.
Corrective & Common Repairs
Recurring 1676 complaints center on its precombustion-chamber injection system and dual gear trains. Coked precombustion chambers and worn injectors cause hard starting, white smoke, and rough idle; clean or renew them as a set rather than one cylinder at a time. Front and rear timing-gear backlash grows with age and throws off valve and injection timing together - inspect both covers, not just one. Turbocharger bearing wear from skipped inspections shows up as boost loss and oil in the exhaust. Aftercooler fouling and coolant leaks round out the list.
Overhaul & Rebuild Points
A 1676 overhaul splits valve-train work up top from block work below. Top-end rework means pulling heads, renewing precombustion chambers, recutting valve seats for the DOHC train, and recalibrating injectors. Reset backlash on both front and rear timing-gear trains before closing the engine - either one left loose reintroduces the timing drift that likely caused the rebuild. Bottom-end work covers reboring, piston and ring renewal, and main and rod bearing replacement. Given the engine's low production volume, sourcing correct rebuild parts is the harder half of any overhaul.
Seasonal & Environment Servicing
As a fully mechanical fuel system with no electronic cold-start aid, the 1676 needs ether-assist or block-heater support for reliable starts in cold weather. Protect the aftercooler's water side with correct coolant and inhibitor levels; scale buildup there is worse in hard-water regions and quietly cuts charge-air cooling. In dusty or off-highway hauling, service the air cleaner more often, since the DOHC valve train and precombustion-chamber injectors both wear faster on dirty intake air. Keep exhaust-side ducting clear in tight cab-over engine bays to limit heat soak on the turbocharger.
1676 common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 9L-3950 | Oil Filter Assembly | Lubrication service | Check fitment → |
| 1S-9547 | Transfer | Lubrication service | Check fitment → |
| 9L-3951 | Oil Filter Assembly | Lubrication service | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
1676 attachments & work tools
Machine type — no work-tool coupling
The 1676 is a standalone V-8 diesel truck engine (introduced 1965, roughly 320-340 hp class), not a self-propelled implement carrier. It has no bucket, blade, fork, or quick-coupler system; its own parts book uses 'Attachments' to mean engine-mounted accessory and drive-mounting hardware, not construction work tools.
Charging and cranking accessory groups
Factory alternator/generator mounting-and-drive groups cover 12-volt and 24-volt charging setups, each paired with a matching electric-starting-motor group sized for the same voltage. Charging voltage is set at build and ties directly to the starting-motor group fitted.
Air compressor mounting
Several air-compressor mounting arrangements are offered to feed the truck's air brake and accessory circuit, including a remote-mounted option split across an assembly-break serial point. Output and mounting style vary by group and by the truck builder's air-system demand; verify against chassis serial range.
PTO / auxiliary drive and torque-converter mounting
An auxiliary drive group and a separate torque-converter mounting group let the flywheel housing drive external equipment (torque-converter transmission or PTO-driven gear) instead of a direct clutch, matching off-highway/hauler-style drivetrains as well as on-highway use. A dedicated hydraulic pump drive-and-mounting group supports engine-driven auxiliary hydraulics such as a dump-body hoist.
Air conditioning (Freon) compressor mounting
A factory drive-and-mounting group accepts a belt-driven Freon-era air-conditioning compressor for cab comfort, fitted as a bolt-on accessory rather than a base-engine item.
Exhaust routing options
Exhaust elbow and elbow-adapter groups are offered in 127 mm (5 in) and 152 mm (6 in) outlet sizes to suit different vertical-stack or turn-down exhaust routing used by different truck body and cab builders.
Cold-start aid
A 12-volt or 24-volt starting-aid glow-plug group is offered as a factory or field-installed option for cold-climate starting, matched to the truck's electrical system voltage.
Oil filtration arrangement
Standard and remote-mounted oil filter assemblies are both offered, letting the chassis builder route the filter away from the block where frame rails or cab layout require it.
Special tool and service-aid group
A dedicated tool group is listed among factory-supported accessories for field maintenance; it is a service aid, not a work tool in the construction-attachment sense, and its contents are chassis/dealer specific.
All 1676 assemblies by section
Every catalogued assembly group for the Caterpillar 1676. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
1676 Diesel Truck Engine
Aftercooler
Air Compressor
Air Compressor (9l2752 N/S)
| 9L***52 | Air Compressor | 1 |
9l5368 Air Compressor Assembly--Part 2 Of 2
| 9L***68 | Air Compressor Assembly | 1 |
9l5368 Air Compressor Assembly--Part 1 Of 2
| 9L***68 | Air Compressor Assembly | 1 |
9l3820 Air Compressor Group
| 9L***20 | Air Compressor Group | 1 |
9l1841 Alternator Assembly--12 Volt, 62 Ampere--End View--Part 1 Of 2--Type 1
| 9L***41 | Alternator Assembly | 1 |
6l6024 Alternator Assembly--Part 2 Of 2--Type 1
| 6L***24 | Alternator Assembly | 1 |
6l6024 Alternator Assembly--Part 2 Of 2--Type 2
| 6L***24 | Alternator Assembly | 1 |
9l1841 Alternator Assembly--12 Volt, 62 Ampere--Side View--Part 2 Of 2--Type 2
| 9L***41 | Alternator Assembly | 1 |
6l6024 Alternator Assembly--Part 1 Of 2--Type 1
| 6L***24 | Alternator Assembly | 1 |
6l6024 Alternator Assembly--Part 1 Of 2--Type 2
| 6L***24 | Alternator Assembly | 1 |
9l1841 Alternator Assembly--12 Volt, 62 Ampere--End View--Part 1 Of 2--Type 2
| 9L***41 | Alternator Assembly | 1 |
9l1841 Alternator Assembly--12 Volt, 62 Ampere--Side View--Part 2 Of 2--Type 1
| 9L***41 | Alternator Assembly | 1 |
Balancer
1s7959 Basic Governor Group--Side View--Part 2 Of 3
| 1S***59 | Basic Governor Group | 1 |
9l3711 Basic Governor Group--Side View--Part 2 Of 3
| 9L***11 | Basic Governor Group | 1 |
1s7959 Basic Governor Group--Top View--Part 1 Of 3
| 1S***59 | Basic Governor Group | 1 |
1s7959 Basic Governor Group--Sectional View Of Housing--Part 3 Of 3
| 1S***59 | Basic Governor Group | 1 |
9l3711 Basic Governor Group--Sectional View Of Housing--Part 3 Of 3
| 9L***11 | Basic Governor Group | 1 |
9l3711 Basic Governor Group--Top View--Part 1 Of 3
| 9L***11 | Basic Governor Group | 1 |
1p7598 Basic Overhaul Kit
| 1P***98 | Basic Overhaul Kit | 1 |
| 1S***85 | Connecting Rod Bearings | 8 |
| 4S***60 | Crankshaft Bearing Replacement Group | 1 |
Breather And Oil Filler
Camshaft--Part 1 Of 2
Camshaft--Part 2 Of 2
Camshaft Drive
9l3293 Air Compressor Assembly--Part 2 Of 2
| 9L***93 | Compressor As | 1 |
9l3293 Air Compressor Assembly--Part 1 Of 2
| 9L***93 | Compressor As | 1 |
Connecting Rod And Piston (1s8643 N/S)--8 Required
| 1S***43 | Connecting Rod And Piston | 1 |
Crankshaft
Crankshaft Bearing Replacement Groups
Cylinder Block And Covers--Rear View--Part 2 Of 3
Cylinder Block And Covers--Front View--Part 1 Of 3
Cylinder Block And Covers--Side View--Part 3 Of 3
Cylinder Block Assembly
Cylinder Block Cover Assemblies
9l3035 Cylinder Head And Valve Mechanism Group
| 9L***35 | Cylinder Head And Valve Mechanism Group | 1 |
9l2943 Exhaust Elbow Group--5 Inch
| 9L***43 | Elbow Group-Exhaust | 1 |
Electric Starting (24 Volt) And Alternator (12 Volt)--Side View
9l4269 Electric Starting And Alternator Group--24 Volt
| 9L***69 | Electric Starting And Alternator Group | 1 |
9l3784 Electric Starting And Alternator Group--12 Volt
| 9L***84 | Electric Starting And Alternator Group | 1 |
Engine Balancer (9l2942 N/S)
| 9L***42 | Engine Balancer | 1 |
Fan And Drive
8h7204 Primary Fuel Filter Group
| 8H***04 | Filter Group-Fuel | 1 |
Flywheel (9l2756 N/S)
| 9L***56 | Flywheel | 1 |
Flywheel
Fuel Filter
2s2882 Primary Fuel Filter Group
| 2S***82 | Fuel Filter Group | 1 |
Fuel Injection Valves And Lines
6l7429 Fuel Priming Pump Group
| 6L***29 | Fuel Priming Pump Group | 1 |
6l7427 Fuel Priming Pump Group
| 6L***27 | Fuel Priming Pump Group | 1 |
3s9620 Fuel Pump Housing Group--Part 1 Of 2
| 3S***20 | Fuel Pump Housing Group | 1 |
3s9620 Fuel Pump Housing Group--Part 2 Of 2
| 3S***20 | Fuel Pump Housing Group | 1 |
3s9620 Fuel Pump Housing Group--Part 1 Of 2--Type 2
| 3S***20 | Fuel Pump Housing Group | 1 |
3s9620 Fuel Pump Housing Group--Part 2 Of 2--Type 2
| 3S***20 | Fuel Pump Housing Group | 1 |
3s9620 Fuel Pump Housing Group--Part 2 Of 2--Type 1
| 3S***20 | Fuel Pump Housing Group | 1 |
3s9620 Fuel Pump Housing Group--Part 1 Of 2--Type 1
| 3S***20 | Fuel Pump Housing Group | 1 |
Fuel Pump Housing, Drive And Governor
Fuel Ratio Control
Fuel Transfer Pump
4s6410 Fuel Transfer Pump Group
| 4S***10 | Fuel Transfer Pump Group | 1 |
Gasket Kits
| 1P***83 | Water Pump | 0 |
| 1P***56 | Valve Grinding | 0 |
| 5S***98 | Diesel Engine Basic | 0 |
Glow Plug And Wiring--12 Volt
Governor Control
9l5203 Governor Control Group--Field Installation
| 9L***03 | Governor Control Group | 1 |
9l4879 Governor Group--Sectional View Of Housing--Part 3 Of 3--Type 1
| 9L***79 | Governor Group | 1 |
9l4879 Governor Group--Side View--Part 2 Of 3--Type 2
| 9L***79 | Governor Group | 1 |
9l4879 Governor Group--Side View--Part 2 Of 3--Type 3
| 9L***79 | Governor Group | 1 |
9l4879 Governor Group--Side View--Part 2 Of 3--Type 1
| 9L***79 | Governor Group | 1 |
9l4879 Governor Group--Sectional View Of Housing--Part 3 Of 3--Type 2--Field Installation
| 9L***79 | Governor Group | 1 |
9l4879 Governor Group--Section View Of Housing--Part 3 Of 3--Type 3
| 9L***79 | Governor Group | 1 |
9l4879 Governor Group--Top View--Part 1 Of 3--Type 3
| 9L***79 | Governor Group | 1 |
9l4879 Governor Group--Top View--Part 1 Of 3--Type 2
| 9L***79 | Governor Group | 1 |
9l4879 Governor Group--Top View--Part 1 Of 3--Type 1
| 9L***79 | Governor Group | 1 |
Governor Torque Spring (9l3627 N/S)--Type 3
| 9L***27 | Governor Torque Spring | 1 |
Governor Torque Spring (9l3627 N/S)--Type 2
| 9L***27 | Governor Torque Spring | 1 |
Governor Torque Spring - Type 1
Manifolds (6l7457 N/S)
| 6L***57 | Manifolds | 1 |
Oil Cooler
Oil Filter And Lines
9l3950 Oil Filter Assembly
| 9L***50 | Oil Filter Assembly | 1 |
Oil Pump And Drive
6l6535 Oil Pump Assembly
| 6L***35 | Oil Pump Assembly | 1 |
8l4477 Oil Pump Assembly
| 8L***77 | Oil Pump Assembly | 1 |
9h2256 Pump Assembly
| 9H***56 | Pump Assembly | 1 |
6l5657 Regulator Assembly
| 6L***57 | Regulator Assembly | 1 |
7l6586 Solenoid Switch Assembly--12 Volt
| 7L***86 | Solenoid As | 1 |
2s900 Starting Motor Assembly--24 Volt--Part 2 Of 2--Type 1
| 2S***00 | Starting Motor As | 1 |
2s900 Starting Motor Assembly--24 Volt--Part 1 Of 2--Type 1
| 2S***00 | Starting Motor As | 1 |
2s900 Starting Motor Assembly--24 Volt--Part 1 Of 2
| 2S***00 | Starting Motor As | 1 |
2s900 Starting Motor Assembly--24 Volt--Part 2 Of 2--Type 2
| 2S***00 | Starting Motor As | 1 |
2s900 Starting Motor Assembly--24 Volt--Part 2 Of 2
| 2S***00 | Starting Motor As | 1 |
2s900 Starting Motor Assembly--24 Volt--Part 1 Of 2--Type 2
| 2S***00 | Starting Motor As | 1 |
9l3597 Electric Starting Motor Assembly--12 Volt--Part 1 Of 2--Type 1
| 9L***97 | Starting Motor Group-Electric | 1 |
9l3597 Electric Starting Motor Assembly--12 Volt--Part 2 Of 2--Type 1
| 9L***97 | Starting Motor Group-Electric | 1 |
9l3597 Electric Starting Motor Assembly--12 Volt--Part 2 Of 2--Type 3
| 9L***97 | Starting Motor Group-Electric | 1 |
9l3597 Electric Starting Motor Assembly--12 Volt--Part 2 Of 2--Type 2
| 9L***97 | Starting Motor Group-Electric | 1 |
9l3597 Electric Starting Motor Assembly--12 Volt--Part 1 Of 2--Type 3
| 9L***97 | Starting Motor Group-Electric | 1 |
9l3597 Electric Starting Motor Assembly--12 Volt--Part 1 Of 2--Type 2
| 9L***97 | Starting Motor Group-Electric | 1 |
Tachometer Drive
6l9614 Tachometer Drive Group
| 6L***14 | Tachometer Drive Group | 1 |
6l9603 Tachometer Drive Group
| 6L***03 | Tachometer Drive Group | 1 |
9l4494 Tachometer Drive Group
| 9L***94 | Tachometer Drive Group | 1 |
Turbocharger And Mounting
9l3062 Turbocharger Assembly
| 9L***62 | Turbocharger Assembly | 1 |
4s9412 Drive Assembly--Variable Timing
| 4S***12 | Variable Timing Drive Group | 1 |
Water Lines (9l2839 N/S)--Front View--Type 2--Part 2 Of 2
| 9L***39 | Water Lines | 1 |
Water Lines (9l2839 N/S)--Side View--Type 2--Part 1 Of 2
| 9L***39 | Water Lines | 1 |
Water Lines (9l2839 N/S)--Side View--Part 1 Of 2
| 9L***39 | Water Lines | 1 |
Water Lines (9l2839 N/S)--Side View--Type 1--Part 1 Of 2
| 9L***39 | Water Lines | 1 |
Water Lines (9l2839 N/S)--Front View--Type 1--Part 2 Of 2
| 9L***39 | Water Lines | 1 |
Water Lines (9l2839 N/S)--Front View--Part 2 Of 2
| 9L***39 | Water Lines | 1 |
6l7446 Water Pump Group
| 6L***46 | Water Pump Group | 1 |
Attachments
9l2920 Exhaust Elbow Adapter Group--5 Inch
| 9L***20 | Adapter Group-Exhaust | 1 |
9l1700 Air Cleaner Group
| 9L***00 | Air Cleaner Group | 1 |
9l2981 Alternator Group--12 Volt, 62 Ampere--Part 1 Of 2
| 9L***81 | Alternator Group | 1 |
9l2981 Alternator Group--12 Volt, 62 Ampere--Part 2 Of 2
| 9L***81 | Alternator Group | 1 |
9l3787 Alternator Mounting And Drive Group
| 9L***87 | Alternator Mounting And Drive Group | 1 |
6l7801 Auxiliary Drive Group
| 6L***01 | Auxiliary Drive Group | 1 |
9l3043 Drive And Freon Compressor Mounting Group--Type 1
| 9L***43 | Drive And Freon Compressor Mounting Group | 1 |
9l3043 Drive And Freon Compressor Mounting Group--Type 2
| 9L***43 | Drive And Freon Compressor Mounting Group | 1 |
9l2921 Exhaust Elbow Group--5 Inch
| 9L***21 | Elbow Group-Exhaust | 1 |
5l7661 Exhaust Elbow Group--5 Inch
| 5L***61 | Elbow Group-Exhaust; Exhaust Elbow Group | 1 |
9l2054 Exhaust Elbow Adapter Group--6 Inch
| 9L***54 | Exhaust Elbow Adapter Group | 1 |
9l2454 Exhaust Elbow Group--6 Inch
| 9L***54 | Exhaust Elbow Group | 1 |
Fan Belts
8h7204 Primary Fuel Filter Group
| 8H***04 | Filter Group-Fuel | 1 |
Freon Compressor Mounting-Fan Driven
9l3689 Generator Mounting Group
| 9L***89 | Generator Mounting Group | 1 |
8f9866 Grease Gun
| 8F***66 | Grease Gun As | 1 |
9l3665 Heat Exchanger Connections Group--Torque Converter
| 9L***65 | Heat Exchanger Connections Group | 1 |
Hydraulic Pump Drive And Mounting
Name Plates And Transfers
| 1H***40 | Transfer; Safety On Dash Or Guards When Used | 1 |
| 1M***98 | Transfer; Filter Instructions On Oil Filter Cover | 1 |
| 1S***80 | Film-Crankcase Oil Filler; On Crankcase Oil Filler Cap | 1 |
9l3951 Oil Filter Assembly
| 9L***51 | Oil Filter Assembly | 1 |
9l3752 Oil Filter Group--Remote Mounted
| 9L***52 | Oil Filter Group | 1 |
9l5338 Oil Pump And Drive Group
| 9L***38 | Oil Pump And Drive Group | 1 |
9l4337 Oil Pump Assembly
| 9L***37 | Oil Pump Assembly | 1 |
9l2567 Oil Pump Assembly
| 9L***67 | Oil Pump Assembly | 1 |
9l2665 Oil Pump And Drive Group--Type 1
| 9L***65 | Oil Pump, Pan And Drive Group | 1 |
9l2665 Oil Pump, Pan And Drive Group--Type 2
| 9L***65 | Oil Pump, Pan And Drive Group | 1 |
3n583 Solenoid Shut-Off Group--12 Volt
| 3N***83 | Shut-Off Group-Solenoid; Solenoid Shut-Off Group | 1 |
6l1923 Rack Solenoid Shut-Off Group--12 Volt
| 6L***23 | Solenoid Shut-Off Group | 1 |
9l4348 Starting Aid Glow Plug Group--24 Volt--Type 1
| 9L***48 | Starting Aid Glow Plug Group | 1 |
9l4348 Starting Aid Glow Plug Group--24 Volt--Type 2
| 9L***48 | Starting Aid Glow Plug Group | 1 |
4m1812 Solenoid Switch Assembly
| 4M***12 | Switch As-Solenoid | 1 |
4l1560 Tool Group
| 4L***60 | Tool Group | 1 |
9l3663 Torque Converter Mounting Group
| 9L***63 | Torque Converter Mounting Group | 1 |
1676 serial number reference
On engines from this era the serial/arrangement tag is a metal plate riveted to the engine block, commonly near the flywheel housing or valve cover (pre-dates the later 17-character PIN format used on newer Cat iron). Read the tag as a 3-character prefix (letters/digits identifying the model and build series) followed by a sequential unit number; the prefix is what ties the engine to the 1676 model line and lets a dealer pull the correct parts book.
| Prefix | Identifies | Notes |
|---|---|---|
| 54B | 1676 Truck Engine - sole documented prefix, no lettered sub-variant (A/B) found | V8, overhead-cam, turbocharged and aftercooled, four valves per cylinder. Bore 114 mm (4.5 in), stroke 140 mm (5.5 in), displacement 11.5 L (700 cu in), rated around 340 hp. Introduced late 1965, using the same bore and stroke as the smaller-bore six-cylinder 1673 truck engine scaled up to eight cylinders. Supplanted by the 1693 (later 3406) inline-six around 1967. Manual titles referencing '54B1-Up' just mark the starting serial within this same prefix run, not a separate prefix. |
Frequently asked questions
What engine does the Caterpillar 1676 use?
The 1676 is not powered by a separate engine - it is the engine. It is an 11.5 L (700 cu in) V8 diesel with a 114 mm x 140 mm (4.5 in x 5.5 in) bore and stroke, a double-overhead-cam valve train with four valves per cylinder driven by separate front and rear timing gear trains, precombustion-chamber fuel injection, and a turbocharger with aftercooling. Factory output runs about 320-340 hp depending on the source and rating point. Caterpillar built it under serial prefix 54B and sold it as a standalone engine to independent Class 8 truck manufacturers.
What is the operating weight of the Caterpillar 1676?
Not applicable in the usual sense - the 1676 is a bare engine, not a complete machine, so it carries no chassis, undercarriage, or operating weight of its own. A dry engine weight is not published in surviving factory literature available today; for a rebuild or installation project, verify actual weight with the truck builder's original spec sheet or a shop that has handled this engine.
What replaced the Caterpillar 1676?
Caterpillar replaced the 1676 around 1967 with the six-cylinder 1693, which Caterpillar later renamed the 3406 - one of its longest-running and best-known truck diesels. The 1676's double-overhead-cam, dual-gear-train V8 layout did not carry forward directly, but its design work became the basis for Caterpillar's later 18-liter 3408 V8.
What 1676 owners discuss
What do diesel mechanics say about the 1676's overall reputation for being worked on?
Why is the 1676 considered rare today, and what does that mean for an owner?
What design features do people point to, and what quirks come with them?
Is there disagreement over the factory horsepower rating?
What's said about the fuel system and oil system on the 1676 - anything owners flag as a weak point?
Does the 1676 have any electrical or sensor issues owners should know about?
What should someone check before buying a truck said to be fitted with an original 1676?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
Need a specific 1676 part?
Search live OEM part data, check fitment, and cross-reference alternatives with Heavy Parts AI.