Connecting Rods & Related Components for Caterpillar 3408 Engines

The Caterpillar 3408 engine is one of the most iconic V8 diesel powerplants in Caterpillar’s 3400 series, used across heavy-duty equipment, marine vessels, oilfield power units, and industrial applications. To keep these engines running at peak performance, properly fitted connecting rods, bearings, bushings, bolts, and nuts are essential. The connecting rod assembly links the piston to the crankshaft, enduring extreme pressure and rotational forces while maintaining precision alignment.

At Diesel Pro Power, we provide OEM-quality connecting rods and related components engineered for the Caterpillar 3408 and its sister engines in the 3400 family, including the 3406 and 3412. Our replacement parts are built to exact specifications, ensuring long-lasting performance under high-load conditions.

Connecting Rod Options for Caterpillar 3408

Straight Rod for Pre-Combustion Engines

This connecting rod is designed for earlier Caterpillar 3408 engines built with pre-combustion chamber configurations. It features a straight design to accommodate older combustion system layouts, ensuring compatibility with legacy equipment still in operation today. These rods are precision-machined to maintain strength and alignment through years of demanding service.

Narrow Taper Rod – 6 Degrees

For later-model Caterpillar 3408 pre-combustion engines, the narrow taper connecting rod provides improved balance and efficiency. The 6-degree taper design reduces stress concentration, offering a smoother transfer of force between the piston and crankshaft. This makes it a popular choice in engines that operate under continuous heavy loads.

Wide Taper Rod for Direct Injection Engines

When Caterpillar transitioned the 3408 to direct injection technology, the connecting rod design evolved as well. The wide taper connecting rod provides superior durability for high-compression direct injection applications, allowing the 3408 to produce greater horsepower and torque output while maintaining reliability.

Connecting Rod Bolts & Nuts for Caterpillar 3408

The connecting rod bolts and nuts are critical fasteners that secure the rod cap to the connecting rod body. Because these parts must withstand extreme cyclical stresses, using high-strength, properly torqued fasteners is vital to prevent rod cap failure.

• Rod Bolts – High-strength bolts manufactured for the 3400-series engines ensure the rod cap remains firmly in place under heavy engine loads. Two bolts are required per connecting rod.

• Rod Nuts – Designed to pair with the rod bolts, these hardened steel nuts lock the cap securely. Two nuts are required per rod.

Replacing bolts and nuts during a rebuild is highly recommended, as reusing worn fasteners can compromise the entire connecting rod assembly.

Connecting Rod Bushings for Caterpillar 3408

Bushings provide a smooth, low-friction surface inside the small end of the connecting rod where the piston pin rides. Properly fitted bushings reduce wear on both the rod and piston pin, helping to extend engine life. Diesel Pro Power offers several bushing options to match rod type and design:

• Bushings for Straight Rods (Pre-Combustion) – Standard-width bushings for older rod designs.

• Bushings for Narrow Taper Rods (6 Degrees) – Sized at approximately 1.59” wide, these bushings are engineered for narrow taper rod configurations.

• Bushings for Wide Taper Rods (Direct Injection) – Wider 1.88” bushings designed for use in direct injection connecting rods, ensuring correct piston pin alignment and smooth operation.

Connecting Rod Bearings for Caterpillar 3408

Rod bearings play a central role in reducing friction between the connecting rod and crankshaft. They act as replaceable wear surfaces, designed to handle high rotational speeds and pressures. Diesel Pro Power supplies both standard and oversize bearings for Caterpillar 3408 engines, covering every rebuild requirement.

Narrow Bearings

These bearings are compatible with straight and narrow taper rods used in pre-combustion engines. Options include:

• Standard Size Bearings – For engines where the crankshaft journals remain within original factory tolerance.

• Oversize Bearings (.010”, .025”, .050”) – For crankshafts that have been ground undersize during overhaul, these bearings restore proper oil clearance and support.

Wide Bearings

Designed for wide taper rods used in direct injection Caterpillar 3408 configurations, wide bearings provide greater surface area and improved load distribution. Options include:

• Standard Size Bearings – Direct replacement for unmodified crankshafts.

• Oversize Bearings (.010”, .025”, .050”) – Allow for precise fitting when crankshaft journals are machined undersize.

Why Quality Connecting Rod Components Matter

The 3408 engine is often tasked with heavy hauling, marine propulsion, and industrial power generation—applications that put extreme stress on its internal components. Using worn or low-quality connecting rod parts can result in:

• Rod cap loosening and catastrophic engine failure.

• Excessive bearing wear leading to crankshaft scoring.

• Increased vibration and reduced performance.

• Shortened overall engine life.

By choosing Diesel Pro Power’s premium connecting rods, bushings, bearings, and fasteners, operators ensure their Caterpillar 3408 engines continue delivering dependable performance under the harshest conditions.

Why Order Caterpillar 3408 Connecting Rods from Diesel Pro Power

When it comes to keeping a Caterpillar 3408 engine running at peak performance, choosing the right replacement parts makes all the difference. The connecting rod is one of the most stressed components in the engine, linking the piston to the crankshaft and transferring the immense forces generated during combustion. If the connecting rod or its related components—such as bushings, bearings, bolts, or nuts—fail, the result can be catastrophic engine damage and extended downtime. That’s why equipment operators around the world trust Diesel Pro Power for their replacement Caterpillar 3408 connecting rod parts.

Trusted by 40,000+ Customers Worldwide

Diesel Pro Power has earned the confidence of more than 40,000 satisfied customers across 180+ countries. Our parts are relied on by ship operators, heavy-equipment contractors, mining companies, oilfield operators, and power generation facilities that cannot afford costly delays. This global customer base reflects not only the quality of the components we provide but also our commitment to keeping businesses running smoothly with minimal downtime.

OEM-Quality Replacements for Caterpillar 3408 Engines

Every connecting rod, bearing, and bushing we supply for the Caterpillar 3408 is manufactured to meet or exceed original Caterpillar specifications. That means you can count on proper fit, durability, and performance every time. These components are designed to withstand the extreme pressures, heat, and vibrations that the 3408 generates under heavy-duty conditions. Whether you are maintaining an older pre-combustion model or a direct-injection version, Diesel Pro Power offers the correct OEM-quality solution.

Fast Worldwide Shipping

In industries where Caterpillar 3408 engines are commonly used—such as marine transport, construction, and industrial power—downtime can be extremely costly. Diesel Pro Power helps reduce downtime by offering rapid shipping options worldwide. No matter where your operation is located, we can deliver connecting rods and related parts quickly and reliably, ensuring your engine is back in service as soon as possible.

A Dedicated Caterpillar 3408 Catalog

Ordering replacement parts can be complicated, especially for engines with multiple design variations like the 3408. That’s why Diesel Pro Power has created a dedicated catalog specifically for Caterpillar 3408 connecting rods and related components. This organized catalog eliminates guesswork, helping you select the correct straight rod, narrow taper rod, or wide taper rod, along with the right bushings, bearings, and fasteners. With our catalog, ordering is simplified and errors are minimized.

Expert Technical Support

Even experienced mechanics sometimes need guidance when selecting engine parts. The specialists at Diesel Pro Power provide expert technical support to ensure you get the exact components required for your specific Caterpillar 3408 build. Whether you are determining which rod design matches your engine model or need assistance identifying the correct bearing oversize, our team is ready to help. This level of personalized support sets us apart and provides additional peace of mind for every order.

The Diesel Pro Power Advantage

By choosing Diesel Pro Power for Caterpillar 3408 connecting rods, you are investing in quality, reliability, and service. With a proven track record of satisfied customers, OEM-quality components, rapid worldwide shipping, a user-friendly catalog, and unmatched technical support, we make it easy to keep your Caterpillar 3408 running at its best.