Caterpillar 3406A Diesel Engine Parts
The CaterpillarÊ3406A is a legendary 14.6_liter, inlineÊ6-cylinder direct-injection diesel engine produced from the early 1970s through 1987. Renowned across trucking, heavy equipment, and industrial/marine power applications, the 3406A delivers robust power (typically 310Ð425_HP) with torque ratings up to ~1,460_lb-ft in high-output configurations. Built with a cast-iron block and head, this engine offers exceptional durability, ease of rebuild, and widespread aftermarket supportÑmaking it a cornerstone of sustainable heavy-duty performance.
3406A Features
- Inline-6 configuration for smooth operation and balanced torque delivery.
- Displacement of approximately 14.6_L (893_cu_in), with bore of ~137_mm and stroke of ~165_mm. [oai_citation:0àCat](https://www.cat.com/en_US/products/new/power-systems/industrial/industrial-diesel-engines/18377764.html?utm_source=chatgpt.com) [oai_citation:1àScribd](https://www.scribd.com/document/605141470/Caterpillar-3406-3406A-3406B-3406C-Truck-Equipment-Data-Sheet?utm_source=chatgpt.com)
- Power output ranging from 310_HP to 425_HP, depending on tuning and application. [oai_citation:2àHeavy Duty Pros](https://www.heavydutypros.com/the-history-of-the-caterpillar-3406-engine.aspx?srsltid=AfmBOooRqFByIcCEs2U-X2bx93JUD_sMfGczIRxhMNYHxqq50392Yluf&utm_source=chatgpt.com) [oai_citation:3àDiesel Rebuild Kits](https://www.dieselrebuildkits.com/cat-3406b-engine-overview-power-and-reliability/?srsltid=AfmBOooeRbophJs2mFHN4fC2SCV4EaMNdtpQ_-epbT4lZfCnO3YeoWUs&utm_source=chatgpt.com)
- Torque up to approximately 1,460_lb-ft in higher-output versions. [oai_citation:4àHeavy Duty Pros](https://www.heavydutypros.com/the-history-of-the-caterpillar-3406-engine.aspx?srsltid=AfmBOooRqFByIcCEs2U-X2bx93JUD_sMfGczIRxhMNYHxqq50392Yluf&utm_source=chatgpt.com) [oai_citation:5àDiesel Rebuild Kits](https://www.dieselrebuildkits.com/cat-3406b-engine-overview-power-and-reliability/?srsltid=AfmBOooeRbophJs2mFHN4fC2SCV4EaMNdtpQ_-epbT4lZfCnO3YeoWUs&utm_source=chatgpt.com)
- Turbocharged and aftercooled variants (3406B, 3406C, 3406E) offer higher power and efficiency. [oai_citation:6àCat](https://www.cat.com/en_US/products/new/power-systems/industrial/industrial-diesel-engines/18377764.html?utm_source=chatgpt.com) [oai_citation:7àHeavy Duty Pros](https://www.heavydutypros.com/the-history-of-the-caterpillar-3406-engine.aspx?srsltid=AfmBOooRqFByIcCEs2U-X2bx93JUD_sMfGczIRxhMNYHxqq50392Yluf&utm_source=chatgpt.com)
- Direct mechanical fuel injection system for reliability and field-serviceability. [oai_citation:8àCat](https://www.cat.com/en_US/products/new/power-systems/industrial/industrial-diesel-engines/18377764.html?utm_source=chatgpt.com) [oai_citation:9àHeavy Duty Pros](https://www.heavydutypros.com/the-history-of-the-caterpillar-3406-engine.aspx?srsltid=AfmBOooRqFByIcCEs2U-X2bx93JUD_sMfGczIRxhMNYHxqq50392Yluf&utm_source=chatgpt.com)
- Durable cast-iron construction supports long service life and rebuildability. [oai_citation:10àCat](https://www.cat.com/en_US/products/new/power-systems/industrial/industrial-diesel-engines/18377764.html?utm_source=chatgpt.com) [oai_citation:11àHeavy Duty Pros](https://www.heavydutypros.com/the-history-of-the-caterpillar-3406-engine.aspx?srsltid=AfmBOooRqFByIcCEs2U-X2bx93JUD_sMfGczIRxhMNYHxqq50392Yluf&utm_source=chatgpt.com)
- Engineered for frequent rebuilds; core parts remain widely available from aftermarket sources. [oai_citation:12àHeavy Duty Pros](https://www.heavydutypros.com/the-history-of-the-caterpillar-3406-engine.aspx?srsltid=AfmBOooRqFByIcCEs2U-X2bx93JUD_sMfGczIRxhMNYHxqq50392Yluf&utm_source=chatgpt.com) [oai_citation:13àDiesel Rebuild Kits](https://www.dieselrebuildkits.com/cat-3406b-engine-overview-power-and-reliability/?srsltid=AfmBOop-3jZxuj-Eh7J-qImk5fa4SFjfuxSPiYBlo9ehK0l_6Dk0xdjD&utm_source=chatgpt.com)
Common Issues and Replacement Parts Needed
- Fuel injectors and mechanical injection pump components wear over time; performance loss and harder starts can occur.
- Turbocharger seals, bearings, and associated gaskets may fail in turbo or aftercooled models under high-hour conditions.
- Engine cooling elements such as water pumps, thermostats, and hoses require routine maintenance to prevent overheating.
- Seals, head gaskets, and valve cover gaskets deteriorate with age, often causing oil or coolant leaks.
- Wear items like pistons, liners, piston rings, rod and main bearings, and crank seals often require replacement during rebuilds. [oai_citation:14àDiesel Pro](https://dieselpro.com/caterpillar-parts/3406-engines/3406-engine-parts.html?srsltid=AfmBOooHrYNYAR0Iz60WHmshl1nVhswS5N-jcobYw6VJrNt1F19Ka7JX&utm_source=chatgpt.com) [oai_citation:15àDiesel Rebuild Kits](https://www.dieselrebuildkits.com/cat-3406b-engine-overview-power-and-reliability/?srsltid=AfmBOop-3jZxuj-Eh7J-qImk5fa4SFjfuxSPiYBlo9ehK0l_6Dk0xdjD&utm_source=chatgpt.com)
Key Replacement Parts for the 3406A Engine
Trusted suppliers including Highway & Heavy Parts (HHP), Diesel Pro Power, Maxiforce, KMP USA, and Diesel Rebuild Kits offer premium-quality replacements such as:
- Complete OVERHAUL KITs & cylinder sets (pistons, piston rings, liners)
- Crankshaft assemblies, camshafts, connecting rods and bearing sets
- Fuel system: injection pumps, calibrated injectors, clamps, and fuel lines
- Cooling & lubrication components: water pumps, oil pumps, oil coolers, thermostats, and filters
- Turbocharger assemblies, exhaust manifolds, and aftercoolers for turbo/DIT versions
- Gaskets & seals: full engine gasket sets, head gaskets, valve covers, crank seals, pan gaskets
- Electrical & accessories: starters, alternators, sensors, marine-rated control cables
Long-block replacement unitsÑincluding basic assembled blocks with pistons, crankshaft, cam, and rodsÑare available, often including core-exchange options with warranty support. [oai_citation:16àATL Diesel](https://atldiesel.com/products/4n2252-caterpillar-3406a-basic-long-block-73e0b146sb?srsltid=AfmBOorY_9Q9I5fnyFoXjsvK79YeGMGM4vczcq8ezKh6d8ZZUN9Q-00v&utm_source=chatgpt.com) [oai_citation:17à4BT Engines](https://4btengines.com/cat-3406-engine/?srsltid=AfmBOoo6hgjwiYAfdamR2YxcFzAJBufHZUqXvU-v_qsR8K1goFhs1eOh&utm_source=chatgpt.com)
The CaterpillarÊ3406A remains one of the most reliable and serviceable heavy-duty diesel engines ever made. For upkeep or overhaul, using top-quality replacement parts ensures continued uptime, consistent torque delivery, and long-term operational value in trucking, marine propulsion, industrial power, and equipment applications.
