3920855
Captive Washer Cap Screw
Cummins®

The Captive Washer Cap Screw, identified by part number 3920855 and manufactured by Cummins, is a specialized fastener designed for use in heavy-duty truck maintenance. Cummins, a renowned name in the engine and power generation industry, produces this component to meet the demanding requirements of commercial truck operations. This screw is integral to ensuring the reliability and efficiency of truck components, playing a significant role in the maintenance and operation of these vehicles.

Basic Concepts

A Captive Washer Cap Screw is a type of fastener that incorporates a washer directly attached to the screw. This design ensures that the washer remains in place during installation, eliminating the risk of loss and ensuring consistent torque application. In mechanical assemblies, these screws are used to secure components together while providing a seal that prevents fluid or gas leakage. The captive washer also distributes the load more evenly across the fastened surfaces, reducing the risk of damage ¹.

Purpose and Role in Truck Operation

The 3920855 Captive Washer Cap Screw is specifically designed to play a vital role in the operation and maintenance of commercial trucks. It is commonly used in areas where secure fastening and sealing are required, such as in the truck’s engine components or structural assemblies. By providing a reliable fastening solution, this screw helps maintain the integrity of critical truck systems, ensuring they operate efficiently and safely ².

Key Features

The 3920855 Captive Washer Cap Screw boasts several distinctive characteristics that enhance its functionality and durability in heavy-duty applications. Its design includes a robust construction that can withstand high levels of stress and vibration, common in truck operations. The integrated washer ensures consistent sealing and load distribution, while the screw’s material is chosen for its strength and corrosion resistance, making it suitable for the harsh environments trucks often encounter ³.

Benefits

Using the 3920855 Captive Washer Cap Screw offers several advantages. It improves assembly efficiency by eliminating the need for separate washers, reducing the risk of washer loss during installation. The integrated washer enhances sealing capabilities, preventing leaks that could compromise truck performance. Additionally, the screw’s design increases resistance to vibration and loosening, ensuring long-term reliability in demanding applications.

Installation Guidelines

Proper installation of the 3920855 Captive Washer Cap Screw is crucial for optimal performance and longevity. Begin by ensuring the mating surfaces are clean and free of debris. Align the screw with the designated hole and use a torque wrench to tighten it to the manufacturer’s specified torque settings. This ensures the screw is securely fastened without over-tightening, which could damage the components or the screw itself.

Troubleshooting and Maintenance

Common issues with Captive Washer Cap Screws include loosening due to vibration and corrosion. To address these problems, regularly inspect the screws for signs of wear or damage. If loosening is detected, re-tighten the screw to the specified torque settings. In cases of corrosion, consider replacing the screw to prevent further degradation. Maintenance tips include keeping the screw and surrounding areas clean and applying a corrosion-resistant coating if necessary.

Manufacturer - Cummins

Cummins Inc. is a global power leader that designs, manufactures, and distributes a wide range of power generation and related technologies. With a history spanning over a century, Cummins has established a reputation for quality, innovation, and reliability in the heavy-duty truck and engine manufacturing industry. Their product range includes engines, filtration systems, and aftermarket parts, all designed to meet the rigorous demands of commercial and industrial applications.

Cummins Captive Washer Cap Screw 3920855 Compatibility

The Cummins Captive Washer Cap Screw part number 3920855 is a versatile component designed to fit a range of Cummins engines. This part is integral to the assembly and maintenance of several engine models, ensuring secure fastening and stability.

4B3.9 and 6B5.9 Engines

The 4B3.9 and 6B5.9 engines both benefit from the use of the 3920855 cap screw. These engines, known for their robust performance, require reliable fastening solutions to maintain operational integrity. The cap screw is used in various applications within these engines, often securing components that are subject to significant stress and vibration.

6C8.3 and QSB5.9 Engines

Similarly, the 6C8.3 and QSB5.9 engines incorporate the 3920855 cap screw in their design. These engines, which are part of Cummins’ lineup of high-performance diesel engines, rely on this part for critical fastening tasks. The cap screw’s design ensures that it can withstand the demanding conditions within these engines, providing a secure and lasting connection.

ISB CM550 and QSB5.9 44 CM550 Engines

The ISB CM550 and QSB5.9 44 CM550 engines also utilize the 3920855 cap screw. These engines are known for their durability and efficiency, and the cap screw plays a key role in maintaining the structural integrity of various engine components. Its use in these engines highlights its importance in ensuring the longevity and reliability of the engine assemblies.

QSC9 CM2250/QSL9 CM2250 Engines

Finally, the QSC9 CM2250 and QSL9 CM2250 engines incorporate the 3920855 cap screw in their design. These engines, which are part of Cummins’ advanced engine series, benefit from the cap screw’s ability to provide a secure fastening solution under high-stress conditions. The cap screw’s design ensures that it can maintain its integrity and performance, contributing to the overall reliability of the engines.

Role of Part 3920855 Captive Washer Cap Screw in Engine Systems

The 3920855 Captive Washer Cap Screw is integral to the secure assembly and operation of various engine components. In fuel systems, it ensures the reliable connection of fuel plumbing to the fuel pump, maintaining a sealed and efficient fuel delivery system. This screw is also pivotal in attaching the fuel supply tube to the injector, guaranteeing that fuel is delivered consistently and under the correct pressure.

Within the injector system, the 3920855 Captive Washer Cap Screw plays a significant role in securing the injector fuel supply tube to the injector itself. This connection is vital for the precise delivery of fuel to the combustion chamber, directly influencing engine performance and efficiency. Additionally, it is used in injector plumbing to ensure all connections are tight and leak-free, which is essential for maintaining the integrity of the fuel system.

For performance parts, such as tube braces, the 3920855 Captive Washer Cap Screw provides the necessary strength and stability to withstand the dynamic forces within the engine compartment. Its use in these applications helps to enhance the structural integrity of the engine, contributing to overall performance and durability.

Conclusion

In summary, the 3920855 Captive Washer Cap Screw is a fundamental component in the assembly and secure operation of various engine systems, ensuring efficient fuel delivery, stable component connections, and enhanced structural integrity.