CAT 3406B Engines for Sale

The CAT 3406B is a 14.6-liter mechanical inline six-cylinder diesel engine that produces 350 to 425 horsepower at 1,800 RPM, with a 6.5-inch stroke and turbocharging for dependable performance. As a fully mechanical engine with no electronic controls, the 3406B is prized for its simplicity, durability, and easy rebuilds. Every 3406B we stock is run-tested, inspected, and listed with its year and horsepower so you can match the right engine to your truck or equipment.

Originally designed by Caterpillar for marine use, the 3406B has since been recommissioned for a wide range of equipment applications. These engines are commonly found in heavy-duty trucks, tractors, combines, and harvesters, and their proven reliability has made them a preferred choice among farmers, owner-operators, and professionals in the agricultural and trucking industries.

Below is a brief overview of the Caterpillar 3406B engine and what makes it a lasting favorite:

Design: The 3406B is a fully mechanical engine with no emissions electronics, which makes it easy to diagnose, service, and rebuild without special software. This simplicity is its greatest strength.

Power and Performance: The engine produces 350 to 425 horsepower from its 14.6-liter displacement, delivering the strong low-end torque that made the 3406 line famous for pulling heavy loads.

Applications: The 3406B powers heavy-duty trucks, agricultural equipment such as tractors and combines, and industrial power units. Many truck versions came equipped with Jake brakes for added control.

Durability: Built with a cast iron block and proven Caterpillar internals, the 3406B is one of the most rebuild-friendly diesel engines ever made. A well-maintained unit can run for decades and be rebuilt many times over.

Parts Availability: Because millions were produced, parts and service support for the 3406B remain wide and easy to source, keeping downtime and repair costs low compared with newer electronic engines.

Why Buy a CAT 3406B From HD Engines?

Owners choose the 3406B because it is a simple, mechanical engine with no emissions electronics to fail, which makes it ideal for older trucks, farm equipment, and industrial power units. At HD Engines, every 3406B is run-tested and inspected before it ships, listed with its serial number, horsepower, and application. With 25-plus years in the diesel engine business and nationwide freight, buying a used 3406B is straightforward and low-risk.

CAT 3406B Engines We Carry:

Our inventory includes both truck and industrial versions of this classic Caterpillar engine, rated from 350 to 425 HP, with run-tested, inspected units and documented serial numbers. These 1980s-era engines keep older trucks and farm equipment running strong. Contact us today and we will match your 3406B by serial number or application. Call (786) 377-5210 or email info@hdengines.com.

Overall, the Caterpillar 3406B has earned a lasting reputation for durability, strong torque, and mechanical simplicity, making it a trusted choice for heavy-duty truck, agricultural, and industrial applications.