GM Genuine Parts Engine Rocker Arm Machined

Description

Product Overview

The GM Genuine Parts engine rocker arm is engineered to the exacting standards of General Motors original equipment. Crafted from premium machined steel, the arm offers superior strength and resistance to wear, ensuring consistent valve actuation over the life of the engine. With a weight of 2.41 pounds and compact dimensions of 24.75 x 9.25 x 8.25 inches, it fits seamlessly into the engine architecture of Chevrolet, Buick, GMC and Cadillac vehicles. The part number 12555270 aligns with the factory specification, guaranteeing a direct replacement that restores original performance characteristics. Its exterior machining provides a precise bearing surface, reducing friction and enhancing the efficiency of the camshaft‑to‑valve interface.

Usage

Designed for both professional service centers and home garages, this rocker arm excels in a variety of environments. Whether you are performing routine maintenance on a daily driver, rebuilding a high‑performance engine, or restoring a classic GM vehicle, the arm delivers reliable operation under normal and elevated temperature conditions. It is particularly suited for drivers who demand dependable acceleration, smooth idle, and reduced engine noise. Installation requires standard tools and follows the OEM torque specifications, making it accessible for seasoned technicians and knowledgeable DIYers alike.

Why Choose Us

GM Genuine Parts are backed by the rigorous engineering and testing protocols of General Motors, ensuring each component meets or exceeds factory tolerances. The rocker arm benefits from continuous updates to material composition and design, reflecting the latest advancements in automotive technology. As an authorized GM part, it carries the assurance of compatibility across a broad model range and is supported by GM’s extensive warranty and service network. Choosing this part means investing in proven durability, precise fit, and the confidence that comes from genuine OEM quality.

Key Features

• Machined steel construction for high strength and wear resistance
• Exact OEM dimensions and fit for Chevrolet, GMC, Cadillac and Buick engines
• Engineered to GM’s strict quality standards and backed by manufacturer warranty
• Optimized bearing surface reduces friction and improves valve timing accuracy
• Easy installation with standard tools and clear torque specifications

FAQ

Is this rocker arm compatible with my 2015 Chevrolet Silverado?

Yes, the part number 12555270 is listed as a direct replacement for the 2015 Chevrolet Silverado’s engine series. Verify the engine code in your vehicle’s service manual to confirm exact compatibility.

Do I need to replace the pushrod when installing this rocker arm?

While not mandatory, it is recommended to inspect the pushrod for wear and replace it if any scoring or deformation is observed. This ensures optimal performance and longevity of the new rocker arm.

What torque specification should be used during installation?

Follow the GM service bulletin for your specific engine model, typically ranging between 12‑15 ft‑lb for the rocker arm mounting bolt. Using a calibrated torque wrench is essential to avoid over‑tightening.

Can this part be used in a performance‑tuned engine?

The machined steel design provides a solid foundation for moderate performance upgrades. For extreme high‑rpm applications, consider consulting a GM performance specialist to verify suitability.

What is the warranty coverage for this rocker arm?

GM Genuine Parts include a limited warranty that covers defects in material and workmanship for up to 12 months or 12,000 miles, whichever occurs first. Registration with the dealer may be required to activate the warranty.