3934921
Rocker Lever
Cummins®

Introduction

The Rocker Lever 3934921 by Cummins is a critical component designed for commercial truck engines. It plays a vital role in the engine’s valve train mechanism, ensuring efficient valve operation and contributing to the vehicle’s overall performance. This part is essential for the engine’s ability to manage valve operations effectively, which is crucial for optimal engine functionality ¹.

Basic Concepts of Rocker Levers

A rocker lever, or rocker arm, is a pivotal component in an engine’s valve train. Its primary function is to transfer motion from the camshaft to the valves, allowing them to open and close at precise intervals. This transfer is achieved through a rocking motion, amplifying the camshaft’s motion to ensure the valves open sufficiently for optimal engine performance. The rocker lever’s significance lies in its ability to maintain the timing and efficiency of valve operations, which are vital for engine performance ².

Role of the 3934921 Rocker Lever in Truck Operation

The 3934921 Rocker Lever by Cummins is specifically engineered to interact with other engine components, such as pushrods and valves. It receives motion from the pushrod, driven by the camshaft, and uses this motion to open and close the valves. The precise design of the 3934921 ensures it can withstand high stresses and temperatures within the engine environment, contributing to the engine’s reliability and efficiency. Its role is to ensure that the valves open and close at the correct times and with the appropriate force, which is essential for the engine’s combustion process ³.

Key Features

The 3934921 Rocker Lever is characterized by its robust design and material composition. It is crafted from high-quality materials that offer durability and resistance to wear and tear. The lever’s design includes features that enhance its performance, such as precise machining for smooth operation and optimal contact with the valves. These attributes contribute to the part’s ability to maintain engine efficiency and reliability over time.

Benefits

The use of the 3934921 Rocker Lever in commercial truck engines offers several advantages. Its design and material characteristics contribute to improved engine efficiency by ensuring precise valve operation. This precision helps maintain the engine’s performance standards and contributes to its longevity. Additionally, the reliability of the 3934921 reduces the likelihood of engine malfunctions, leading to lower maintenance costs and increased uptime for commercial trucks.

Troubleshooting and Maintenance

Common issues associated with rocker levers include wear, improper adjustment, and failure due to material fatigue. Diagnostic procedures for these issues involve checking the lever’s condition, ensuring proper clearances, and verifying its operation within the valve train. Maintenance practices for the 3934921 include regular inspection for signs of wear or damage, proper lubrication, and adjustment to maintain optimal performance. These practices help ensure the longevity and efficiency of the rocker lever and, by extension, the engine it serves.

Compatibility of Rocker Lever Part 3934921 with Cummins Engines

The Rocker Lever part 3934921, manufactured by Cummins, is designed to fit a range of Cummins engines. This part is crucial for the proper functioning of the engine’s valve train system, ensuring smooth and reliable operation.

Group 1: C Series Engines

• 6C8.3
• C8.3 G
• G8.3
• G8.3 CM558

The Rocker Lever part 3934921 is compatible with the C series engines, including the 6C8.3, C8.3 G, G8.3, and G8.3 CM558. These engines are known for their robust design and are commonly used in various industrial and commercial applications.

Group 2: L Series Engines

• L GAS PLUS CM556
• L8.9G CMOH2.0 L125B
• L9.3 L105

The Rocker Lever part 3934921 also fits the L series engines, such as the L GAS PLUS CM556, L8.9G CMOH2.0 L125B, and L9.3 L105. These engines are designed for heavy-duty applications and are known for their durability and performance.

Group 3: QSL Series Engines

• QSL9 G CM558

The Rocker Lever part 3934921 is also suitable for the QSL9 G CM558 engine. This engine is part of the QSL series, which is designed for high-performance and reliability in demanding environments.

Group 4: GTA Series Engines

• GTA8.3 CM558

The Rocker Lever part 3934921 is compatible with the GTA8.3 CM558 engine. This engine is part of the GTA series, known for its advanced technology and efficiency.

Group 5: ISL Series Engines

• ISL G CM2180

The Rocker Lever part 3934921 fits the ISL G CM2180 engine. This engine is part of the ISL series, which is renowned for its power and reliability in heavy-duty applications.

Each of these engines benefits from the precision and reliability of the Rocker Lever part 3934921, ensuring optimal performance and longevity of the engine’s valve train system.

About Cummins

Cummins Inc. is a global power leader that designs, manufactures, and distributes a wide range of power solutions, including diesel and natural gas engines, as well as related technologies. With a history spanning over a century, Cummins has established itself as a leader in the automotive industry, known for its commitment to innovation, quality, and customer satisfaction. The company’s expertise in diesel engine manufacturing is evident in its product offerings, which are designed to meet the demanding requirements of commercial and industrial applications.

Conclusion

The 3934921 Rocker Lever by Cummins is an essential component in the operation of various engine systems, facilitating the transfer of motion from the camshaft to the valves. Its precise design and robust material composition ensure efficient and reliable valve operation, contributing to the overall performance and longevity of the engine. Regular maintenance and proper adjustment of this part are crucial for maintaining engine health and ensuring optimal performance.