Remanufactured CAT 3406 14.6L (893 ci) Engine For Sale
1973–1999 — 310–550 hp | 1,100–1,850 lb-ft
The Caterpillar 3406 is arguably the most legendary diesel engine in American trucking history. Produced from 1973 to 1999 across three generations — the 3406A (1973–1987), 3406B (1987–1993), and 3406...
Starting from $6,000 – $12,000 — 1-Year Unlimited Mileage Warranty
CAT 3406 Technical Specifications
About the Caterpillar 3406 Engine
The Caterpillar 3406 is arguably the most legendary diesel engine in American trucking history. Produced from 1973 to 1999 across three generations — the 3406A (1973–1987), 3406B (1987–1993), and 3406E (1993–1999) — this 14.6-liter inline-six powered millions of trucks, construction machines, marine vessels, and generators. The mechanical 3406B is revered for its simplicity and bulletproof reliability, while the electronically-controlled 3406E became the first fully electronic heavy-duty diesel engine from Caterpillar, offering precise fuel control and horsepower ratings up to 550 hp. The 3406E's Electronic Unit Injection (EUI) system was revolutionary for its time, providing better fuel economy and lower emissions than the mechanical 3406B while maintaining the legendary CAT durability. The 3406 was succeeded by the C15 in 1999, but these engines remain in active service worldwide, with many 3406B and 3406E engines having accumulated well over a million miles.
CAT 3406 Strengths
- Legendary reliability — the 3406B is considered one of the most reliable diesel engines ever built
- Simple mechanical design (3406A/B) makes maintenance straightforward and affordable
- The 3406E was the first electronic CAT engine, offering precise fuel control and diagnostics
- No EGR, no DPF, no complex emissions equipment on any 3406 variant
- Massive aftermarket parts availability — virtually every component is readily available
- Proven million-mile durability with proper maintenance
Common CAT 3406 Issues (Addressed in Our Remanufactured Engines)
- Oil pan rail cracking on early 3406E blocks (5EK serial number prefix)
- Crankshaft failures on some 6TS serial number 3406E engines (known bad batch)
- Mechanical injection pump wear on high-mileage 3406A/B engines
- Turbocharger bearing failures on high-hour engines
- Cylinder liner pitting from poor coolant maintenance (SCA levels critical)
- Camshaft and lifter wear on engines with extended oil change intervals
Vehicles with the CAT 3406
Available CAT 3406 Remanufactured Engines
CAT 3406 Buying Guide
When purchasing a remanufactured Caterpillar 3406, identify the generation: 3406A (mechanical, 1973–1987), 3406B (mechanical, 1987–1993), or 3406E (electronic, 1993–1999). The 3406B is the most popular for its simplicity, while the 3406E offers more power and electronic diagnostics. For the 3406E, avoid the 5EK serial number prefix (known for oil pan rail cracking) and some 6TS serial numbers (crankshaft issues). The 2WS prefix is generally considered the best 3406E variant. A quality remanufactured 3406 should include new injectors (or rebuilt injection pump for A/B models), rebuilt turbo, new cam followers, and a complete gasket set.
Frequently Asked Questions — CAT 3406
How much does a remanufactured Caterpillar 3406 engine cost?
A remanufactured Caterpillar 3406 engine typically costs between $9,500 and $13,000 depending on the generation (3406A, 3406B, or 3406E), horsepower rating, and condition. The 3406E generally costs more than the mechanical 3406B due to its electronic components. All our CAT 3406 engines are fully dyno tested and backed by our comprehensive warranty. Call (631) 991-7700 for an exact quote.
What is the difference between 3406B and 3406E?
The 3406B (1987–1993) uses a mechanical injection pump and is valued for its simplicity — no electronics, no sensors, just a reliable mechanical diesel. The 3406E (1993–1999) introduced Electronic Unit Injection (EUI) with an ECM computer, providing precise fuel control, better fuel economy, and diagnostic capabilities. The 3406E offers more power (up to 550 hp vs 425 hp) but is more complex. Both are excellent engines.
Is the CAT 3406 a good engine?
The Caterpillar 3406 is widely regarded as one of the greatest diesel engines ever produced. The 3406B is legendary for its simplicity and reliability, while the 3406E is known for its power and durability. Many 3406 engines have exceeded 1,000,000 miles with proper maintenance. The 3406's no-emissions design (no EGR, no DPF) makes it one of the most reliable and easy-to-maintain heavy-duty diesels available.
What trucks use the Caterpillar 3406 engine?
The Caterpillar 3406 was installed in virtually every major Class 8 truck from 1973 to 1999, including Peterbilt 379/362/377, Kenworth W900/T800/T600, Freightliner FLD120/Classic, International 9300/9400, and Western Star trucks. It was also widely used in construction equipment, marine vessels, and power generation applications.
How many miles can a CAT 3406 last?
A well-maintained Caterpillar 3406 can last 750,000 to over 1,000,000 miles before requiring a major overhaul. The 3406B is particularly known for exceptional longevity due to its simple mechanical design. Many owner-operators have reported 1.5 million miles or more on original 3406B engines with regular rebuilds. The 3406E is similarly durable with proper electronic system maintenance.
Which 3406E serial numbers should I avoid?
The 5EK serial number prefix is known for oil pan rail cracking issues. Some 6TS serial numbers had a run of defective crankshafts. The 2WS prefix is generally considered the best and most reliable 3406E variant. When purchasing a remanufactured 3406E, our engines address all known serial number issues with updated and inspected components, so the serial prefix is less of a concern.
Caterpillar Troubleshooting Guides
Caterpillar C15 Problems
ACERT vs pre-ACERT issues, injector failures, head gaskets, and oil pressure problems.
Read Guide →Diesel Engine Cost Guide
Complete pricing for remanufactured Caterpillar engines by model.
Read Guide →Reman vs Rebuilt Engines
Which option is right for your CAT? Compare quality, cost, and warranty.
Read Guide →Installation Guide
Step-by-step guide for installing your remanufactured engine.
Read Guide →