Caterpillar 3406

Caterpillar 3406 Engine Parts Catalog

Aftermarket Parts for the Original CAT 3406 Engine

The Caterpillar 3406 is one of CAT’s most iconic heavy-duty diesel engines. Designed for marine, industrial, and generator applications, this inline 6-cylinder platform is known for its long service life and ease of maintenance. Diesel Pro Power is proud to support the original version of the 3406 — excluding later B, C, and E series — with a complete inventory of high-quality aftermarket parts.

All components are in stock and available for worldwide shipping within 24 hours.

Engine Overhaul Kit for Caterpillar 3406

• Complete in-frame and out-of-frame kits

• Includes pistons, liners, rings, wrist pins, rod and main bearings, and full gasket set

• Designed for long-term durability and factory-spec compression recovery

Gauges for Caterpillar 3406

• Oil pressure, coolant temperature, tachometers, voltmeters, and boost gauges

• Mechanical and electric options for marine and industrial panels

• Compatible senders available

Engine Water Pump for Caterpillar 3406

• Replacement water pumps with cast impeller

• Includes gaskets and bolts for installation

• Maintains coolant flow and operating temperature

Marine Water Pump for Caterpillar 3406

• Raw water pumps for saltwater or heat exchanger setups

• Bronze impellers and marine-grade seals

• Available as complete assemblies or rebuild kits

Cylinder Head for Caterpillar 3406

• Aftermarket cylinder heads for the original 3406

• Available fully assembled with valves, springs, guides, and seats

• Milled and inspected for proper sealing and combustion

Fuel Components for Caterpillar 3406

• Mechanical fuel pumps and priming systems

• Fuel shutoff solenoids, injection hardware, and return lines

• All components designed to meet factory flow and pressure

Injectors for Caterpillar 3406

• Unit injectors compatible with original CAT 3406 timing and spray pattern

• Includes O-rings, seals, and installation clamps

• Designed for clean atomization and consistent delivery

Turbo for Caterpillar 3406

• Direct replacement turbochargers

• Options for standard duty and high-flow marine versions

• Includes turbo gaskets, oil lines, and mounting hardware

Intercooler / Aftercooler for Caterpillar 3406

• Charge air coolers for turbocharged engine configurations

• Marine and stationary options

• Includes gaskets and mounting brackets

Oil System Components for Caterpillar 3406

• Oil pumps, pans, dipsticks, and coolers

• High-capacity flow matched to original engine specs

• Includes gaskets and oil pressure regulators

Crankshaft for Caterpillar 3406

• Balanced and magnaflux-inspected crankshafts

• Available in standard and undersize journals

• Includes thrust washers, front/rear seals, and keyways

Camshaft for Caterpillar 3406

• OEM-profile aftermarket camshafts

• Includes cam bushings, lifters, followers, and thrust hardware

• Precision-matched to original fuel and valve timing

Engine Piston Kit for Caterpillar 3406

• Complete piston sets with rings, wrist pins, and circlips

• Standard and oversize pistons available

• Engineered for factory compression and fit

Connecting Rod for Caterpillar 3406

• Forged connecting rods with pre-installed bushings

• Compatible with factory piston and crankshaft setups

• Remanufactured and new options available

Exhaust for Caterpillar 3406

• Exhaust manifolds (wet/dry), elbows, mufflers, and turbo outlets

• Marine-rated components built for corrosion resistance

• Includes flange kits, clamps, and heat-shield gaskets

Gasket Kits for Caterpillar 3406

• Full engine gasket kits (top and bottom end)

• Head gaskets, valve cover, intake/exhaust, oil pan, crank seals

• Heat- and oil-resistant materials suitable for marine and industrial use

Sensor & Switch for Caterpillar 3406

• Oil pressure switches, temperature sensors, shutdown solenoids, ignition switches

• Compatible with marine panels and alarm systems

• Marine-safe, sealed contacts available

Starter & Alternator for Caterpillar 3406

• 12V and 24V gear-reduction starters

• High-output alternators with internal or external regulation

• Solenoids, voltage regulators, and mounting brackets

Fuel Filter for Caterpillar 3406

• Primary and secondary spin-on or cartridge filters

• Fuel/water separators, filter heads, and mounting hardware

• Designed to protect injectors from particulate and moisture contamination

Oil Filter for Caterpillar 3406

• OEM-fit spin-on oil filters

• High-capacity filtration for extended service life

• Filter bases and bypass adapters available

33C Marine Cable (3/16") for Caterpillar 3406

• Push-pull throttle and shift cables for marine control

• Stainless steel core and low-friction jacket

• Compatible with standard marine levers

43C Marine Cable (1/4") for Caterpillar 3406

• Heavy-duty control cables for throttle or clutch operation

• Saltwater-resistant jacket and sealed ends

• Designed for rugged marine use

Industrial Cable for Caterpillar 3406

• Cables for industrial throttle, PTO, and governor control

• Available in various lengths and end configurations

• Suitable for generators, pumps, and remote panels

Paint & Sealant for Caterpillar 3406

• High-temperature Caterpillar yellow enamel

• Gasket adhesives, thread sealant, anti-seize compounds

• Marine-safe and oil-resistant formulas

Twin Disc Transmissions That Pair To The Caterpillar 3406

• Twin Disc marine transmission parts & rebuilt transmissions

• Couplings, damper plates, PTO adapters, and clutch assemblies

• Compatible with CAT 3406 engine-to-gearbox connections

Why Diesel Pro Power?

• Trusted by over 40,000 customers globally

• All parts are aftermarket, engineered to OEM-quality standards

• Fast 24-hour global shipping

• Clean navigation and expert technical support

 

Engine Specifications & Applications of the Caterpillar 3406 Engine

Overview of the Original Caterpillar 3406 Engine

The Caterpillar 3406 is a mechanically governed, inline six-cylinder diesel engine that debuted in the mid-1970s and quickly became one of Caterpillar’s most iconic platforms. Before the evolution into the B, C, and E series, the original 3406—also known as the Pre-B model—established a reputation for mechanical simplicity, robust performance, and dependable torque in heavy-duty operations.

Built for power and serviceability, the early 3406 featured a dry cylinder block, direct injection fuel system, and mechanical fuel control. The engine was designed with a broad operating window and delivered consistent horsepower at various RPM ranges. While later variants added electronic fuel control and emissions compliance, the original 3406 remained a pure mechanical workhorse, ideal for marine, industrial, and power generation use.

Even decades after its introduction, the original 3406 is still in service around the world—especially in applications where Tier compliance is not mandatory and reliability is paramount.

Caterpillar 3406 Engine Specifications (Original Version)

Specification	Details
Engine Configuration	Inline 6-cylinder, 4-stroke diesel
Displacement	14.6 Liters (893 cubic inches)
Bore x Stroke	5.4 in x 6.5 in (137 mm x 165 mm)
Compression Ratio	14.5:1 to 15.3:1 (varies by build and rating)
Aspiration Options	Turbocharged or Turbocharged with Aftercooler
Horsepower Range	250–475 HP @ 1,800–2,100 RPM
Max Torque Range	800–1,300 lb-ft @ 1,200–1,600 RPM
Fuel System	Mechanical Unit Injector
Cooling System	Water-cooled
Emissions Compliance	Pre-Tier / Non-regulated
Dry Weight (approx.)	2,700–3,000 lbs

Notable Design Features

• Dry cylinder block with no liner flanges—designed for rigid strength and rebuild efficiency

• Gear-driven camshaft and accessory drive—eliminates belt failure concerns

• Modular fuel and air systems for easier service in the field

• Mechanical injection system—fully serviceable without electronic diagnostics

• Long service intervals and rebuildable bottom end (crank, rods, liners)

The 3406’s platform stability, high torque output, and mechanical architecture made it a favorite among diesel mechanics and operators seeking control, durability, and uptime.

Applications of the Caterpillar 3406 Engine

The original CAT 3406 was deployed across a wide spectrum of demanding industries. Its high displacement and mechanical dependability gave it a central role in powering vessels, generators, and industrial machinery. These engines were typically used in conditions where load stability, fuel economy under heavy use, and ease of mechanical servicewere critical.

1. Marine Propulsion and Auxiliary Power

The 3406 was one of Caterpillar’s most widely used engines in marine environments. Known for its ability to hold torque under load, the 3406 powered both propulsion systems and onboard auxiliary machinery.

Common Marine Applications:

• Coastal cargo vessels, harbor tugs, and push boats

• Shrimp boats and commercial fishing trawlers

• Workboats, pilot boats, and patrol vessels

• Hydraulic pump drives and marine fire suppression systems

• Marine generator sets in the 125–250 kW range

Operators preferred the original 3406 for its excellent low-end torque, essential for pushing heavy hulls and operating in adverse sea conditions. Many of these engines are still in use on the water today, often as part of repower projects for vessels originally equipped with less efficient or harder-to-service engines.

2. Industrial Equipment & Heavy-Duty Power Units

In industrial use, the 3406 engine was a mainstay of heavy-duty stationary and mobile equipment, especially in oilfield, mining, and construction sectors.

Industrial Equipment Applications:

• Drilling rig engines and mud pump drives

• High-volume irrigation and dewatering systems

• Mining auxiliary power units

• Portable and skid-mounted compressor stations

• Conveyor belt power units in large-scale quarry operations

The 3406’s broad torque curve and rugged build made it ideal for continuous-duty industrial work, particularly in environments with fluctuating loads and long operational cycles.

3. Generator Sets (Prime and Standby Power)

The original 3406 was widely used in diesel-powered generator sets, where its displacement and mechanical stability provided clean, dependable power across a wide output range.

Power Generation Uses:

• Prime power for off-grid operations (oil camps, mining, telecom)

• Emergency backup for hospitals, industrial facilities, and data centers

• Mobile generator trailers used in disaster recovery and infrastructure support

• Generator sets in marine engine rooms or shipboard auxiliary systems

Output ratings for 3406-powered generators typically ranged between 200–300 kW, depending on configuration and application. Operators chose the 3406 when reliability and fuel efficiency under load were top priorities.

4. Agricultural and Utility Applications

The 3406 also played a role in agricultural settings, where high-horsepower diesel power was required for belt-driven systems, large equipment, and irrigation setups.

Agricultural Applications:

• High-lift diesel water pumps for flood irrigation

• Diesel power for crop dryers and feed mixers

• Large grain elevators and conveyance systems

• Belt-driven agricultural processing machinery

• Stationary engines used on sugar cane and rice farms

Its mechanical design made it especially desirable in rural or remote farming operations, where access to diagnostic tools or electronic parts was limited.

5. Global Repower & Export Use

The original 3406, thanks to its pre-emissions mechanical setup, is frequently repurposed in repower projects around the world. The engine remains ideal for fleets operating in areas without stringent emissions laws.

Common Repower Scenarios:

• Marine vessels converting from obsolete Detroit Diesel or Cummins platforms

• Exported generators for emerging markets

• Utility trailers and pump units for developing regions

• Custom-built heavy equipment requiring dependable diesel power

Many operators specifically seek the 3406 due to its robust aftermarket support, ease of overhaul, and ability to run cleanly on varied fuel quality without DEF, EGR, or DPF systems.

Final Thoughts

The original Caterpillar 3406 engine continues to be respected worldwide for its mechanical integrity, torque-rich performance, and field-serviceable architecture. Its long-running production life and wide application range prove its value across the marine, industrial, generator, and agricultural sectors.

Today, the 3406 remains a go-to choice for operators who value engine rebuildability, fuel efficiency under load, and the ability to operate without electronics. Whether it's powering a fishing trawler or generating electricity at a mining camp, the 3406 has proven itself to be one of Caterpillar’s most trusted engine designs.

For operations that demand dependable mechanical power with zero compromise, the Caterpillar 3406 delivers—then and now.

 

Additional Resources

Marine CAT 3406 Component Maintenance Life

The Legacy of the Caterpillar Marine 3406 Engine: A Retrospective

Everything You Need to Know About the Caterpillar 3406 Marine Engine