Ford was one of the first OEMs to pioneer cracked connecting rods, also known as fracture-split connecting rods, in the 90s. And they're now a trusted choice in manufactured and rebuilt engine. 

Their name comes from the unique method of separating the big-end bore. The rod is intentionally cracked at a pre-weakened point. This technique creates a natural, interlocking surface that ensures a precise and strong fit during reassembly.

Although originally produced for passenger vehicles and light commercial engines, cracked rods offer benefits for all engine builders. They provide accurate alignment, high durability, and excellent repeatability at a lower cost than traditional forged alternatives.

How Are Cracked Connecting Rods Made? 

Cracked connecting rods are usually made from forged steel, but sometimes also from metal powder using powder metallurgy. The big-end bore is drilled first, then intentionally fractured using hydraulic force or an impact device to separate the rod and cap. This controlled break produces a unique, jagged, or bumpy mating surface that's more precise since the fragments can only connect in one particular manner.
Once installed, the bolts or fasteners provide the clamping force to hold the two parts securely and almost seamlessly in place.

Proper Installation of Cracked Connecting Rods

Installing cracked (or fractured) connecting rods requires careful handling and precise assembly to ensure optimal engine performance. These rods are typically manufactured as a single forged piece and then cracked apart along a predetermined fracture line—this process must often still be done before use. The resulting interlocking surfaces ensure perfect alignment when the rod and cap are reassembled. Before installation, ensure all surfaces are clean and free of debris. Align the two parts exactly along the fracture lines, insert the correct bearings, and torque the bolts to the manufacturer’s specifications. Always use new bolts. Once installed, verify proper clearance and ensure smooth rotation around the crankshaft journal. Properly preparing and installing cracked connecting rods is essential for engine durability and performance.

What Are the Advantages of Cracked Connecting Rods?

What Are the Limitations? 

Cracked rods are highly effective but may not suit every engine type:

• Limited Reusability: Once cracked, the rod and cap must remain a matched set.
• Require Careful Handling: If you drop the connecting rod or modify it, they will no longer fit perfectly.
• Not ideal for highly tuned or performance applications: Forged or billet rods may be preferred for performance applications.

Still, for most OEM and aftermarket rebuilds, cracked rods provide the right balance of precision and durability.

Applications and Availability 

Cracked connecting rods are widely used in today’s engine platforms, especially from European and Japanese manufacturers. They are well-suited for:

• Passenger Cars and Light Commercial Vehicles
• Medium-Duty Diesel Engines

Wilmink Engine Parts biedt een uitgebreid assortiment gebroken drijfstangen van vertrouwde merken als BF Original en Wilmink Engine Parts Private Label, die allemaal voldoen aan de OE-specificaties.

Got questions? Contact one of our product specialists at sales@wilminkgroup.com.