3068390
Push Rod
Cummins®

Introduction

The Cummins 3068390 Push Rod is a critical component in heavy-duty truck engines, designed to facilitate the operation of the valves by transmitting motion from the camshaft to the rocker arms. This ensures precise valve timing and operation, which is essential for the engine’s performance and efficiency.

Basic Concepts of Push Rods

Push rods are mechanical links used in overhead valve (OHV) engines to transfer motion from the camshaft to the valves. Positioned between the camshaft and the rocker arms, push rods convert the rotational motion of the camshaft into linear motion that operates the valves. This mechanism is fundamental for efficient valve actuation, which is vital for the engine’s combustion process ¹.

Purpose of the Cummins 3068390 Push Rod

The Cummins 3068390 Push Rod is engineered to enhance the valve train’s functionality in heavy-duty engines. It ensures that the valves open and close at the correct times, which is fundamental to the engine’s ability to maintain optimal performance, fuel efficiency, and emissions control.

Key Features

The Cummins 3068390 Push Rod is distinguished by its robust material composition and design. Crafted from high-quality steel, it offers exceptional durability and resistance to wear. Its design includes precise tolerances to ensure smooth operation and minimal friction, which contributes to the engine’s overall efficiency and longevity. Additionally, the push rod’s surface treatment enhances its resistance to corrosion and fatigue, further ensuring reliable performance under demanding conditions ².

Benefits

The use of the Cummins 3068390 Push Rod in an engine’s valve train offers several advantages. It contributes to improved engine efficiency by ensuring precise valve timing and operation. The push rod’s durable construction and design also enhance the engine’s reliability and longevity, reducing the need for frequent replacements or repairs. Compared to other push rod designs, the Cummins 3068390 offers superior performance and durability, making it a preferred choice for heavy-duty applications.

Troubleshooting and Maintenance

Common issues with push rods may include wear, bending, or failure due to fatigue. Symptoms of push rod failure can manifest as engine misfires, reduced performance, or unusual noises from the valve train. Diagnostic procedures involve inspecting the push rod for signs of wear or damage and checking the valve train’s operation. Regular maintenance, including periodic inspection and replacement as needed, is recommended to ensure optimal performance and prevent unexpected failures ³.

Installation and Replacement

Installing or replacing the Cummins 3068390 Push Rod requires careful attention to detail to ensure proper fitment and functionality. The process involves removing the old push rod, inspecting the camshaft and rocker arm contacts for wear, and installing the new push rod with the correct orientation. Tools required may include a push rod length gauge to ensure the new push rod is the correct length, and torque wrenches for securing related components. Following manufacturer guidelines for installation and torque specifications is crucial to maintain the engine’s performance and reliability.

Cummins Overview

Cummins Inc. is a global power leader that designs, manufactures, and distributes engines, filtration, and power generation products. With a strong reputation in the automotive industry, Cummins is committed to delivering high-quality components for heavy-duty trucks. The company’s focus on innovation, quality, and customer satisfaction has established it as a trusted name in the industry, providing reliable and efficient solutions for demanding applications.

Compatibility with Cummins Engines

The Cummins Push Rod part number 3068390 is designed to fit a variety of Cummins engines, ensuring compatibility and performance across multiple engine models. Here is a detailed breakdown of the engines with which this push rod is compatible:

ISM Series Engines

• ISM CM570
• ISM CM570/870
• ISM CM876
• ISM11 CM876 SN

QSM11 Series Engines

• QSM11 CM570
• QSM11 CM876

M11 Series Engines

• M11 CELECT
• M11 CELECT PLUS
• M11 MECHANICAL

L10 Series Engine

• L10 CELECT

This part is integral to the valve train mechanism, ensuring proper valve operation and engine performance across these various engine models.

Role of Part 3068390 Push Rod in Engine Systems

The Cummins 3068390 Push Rod is an essential component in the valve train mechanism of an engine. It operates in conjunction with the lever and rocker to facilitate the opening and closing of the engine’s valves.

When the camshaft rotates, it actuates the lever, which in turn moves the rocker. The rocker is connected to the push rod, which transmits the motion to the valve. This sequence ensures precise timing and efficient operation of the valve, allowing for optimal air and fuel mixture intake and exhaust gas expulsion.

The push rod’s role is to convert the rotational motion of the camshaft into linear motion, which is then amplified by the rocker and transferred to the valve. This mechanism is fundamental for maintaining the engine’s performance and efficiency. The push rod must be durable and accurately machined to withstand the high stresses and temperatures within the engine compartment, ensuring reliable operation over the engine’s lifespan.

Conclusion

The Cummins 3068390 Push Rod plays a vital role in the valve train mechanism of heavy-duty engines, ensuring precise valve timing and operation. Its robust design, durable construction, and compatibility with various Cummins engines make it a critical component for maintaining engine efficiency and reliability. Regular maintenance and proper installation are essential to ensure optimal performance and longevity of the engine.