3904784
Timing Lock Screw
Cummins®

The Timing Lock Screw 3904784, manufactured by Cummins, is a specialized component designed for use in heavy-duty truck engines. This screw plays a role in ensuring the precise alignment and synchronization of engine components, which is vital for the efficient operation of the engine ¹. Cummins, a well-established name in the engine manufacturing industry, is known for its commitment to quality and innovation, making the 3904784 Timing Lock Screw a reliable choice for maintaining engine performance.

Basic Concepts of Timing Lock Screws

A Timing Lock Screw is a component used in the engine to secure the timing mechanism in place. It interacts with other timing components such as gears, chains, or belts to maintain the correct timing of the engine’s valves and pistons ². The basic principle behind engine timing involves the precise coordination of the opening and closing of valves with the movement of the pistons. Locking screws play a role in this system by ensuring that the timing components remain in the correct position, thus allowing the engine to operate smoothly and efficiently.

Purpose of the 3904784 Timing Lock Screw

The 3904784 Timing Lock Screw is designed to ensure the proper alignment and synchronization of engine components in heavy-duty truck engines. By securing the timing mechanism, it helps maintain the precise timing of valve operations in relation to piston movements. This alignment is crucial for the engine’s performance, fuel efficiency, and longevity ³. The screw’s role in maintaining this synchronization contributes to the overall reliability and efficiency of the engine.

Key Features

The 3904784 Timing Lock Screw features a robust material composition that enhances its durability and performance. Its design specifications are tailored to meet the demanding conditions of heavy-duty truck engines, ensuring it can withstand high stress and temperatures. Unique attributes of this screw include its precision machining and high-quality materials, which contribute to its reliability and longevity in engine applications.

Benefits

Using the 3904784 Timing Lock Screw offers several benefits, including improved engine performance, enhanced reliability, and easier maintenance. By ensuring precise timing alignment, the screw contributes to smoother engine operation and better fuel efficiency. Its durable construction reduces the need for frequent replacements, making maintenance more straightforward and cost-effective. These benefits collectively contribute to the overall efficiency and longevity of the engine.

Installation Process

Proper installation of the 3904784 Timing Lock Screw involves several steps to ensure it is correctly positioned and secured. Begin by preparing the engine and timing components according to the manufacturer’s guidelines. Use the appropriate tools to install the screw, ensuring it is tightened to the specified torque settings. Follow any special procedures outlined in the installation manual to guarantee the screw is properly installed and functions as intended.

Troubleshooting and Maintenance

Common issues with Timing Lock Screws may include loosening over time or damage due to wear and tear. Regular maintenance practices, such as periodic inspections and torque checks, can help ensure the screw remains in optimal condition. If issues are identified, such as misalignment or damage, it is important to address them promptly to prevent further engine problems. Following the manufacturer’s guidelines for maintenance and troubleshooting can help maintain the screw’s performance and longevity.

Cummins: Manufacturer Overview

Cummins Inc. is a leading manufacturer of engine components with a strong reputation for quality and innovation in the automotive industry. Founded with a commitment to excellence, Cummins has built a legacy of producing reliable and high-performance engine parts. Their expertise in engine technology and dedication to continuous improvement make them a trusted name in the industry, ensuring that components like the 3904784 Timing Lock Screw meet the highest standards of quality and performance.

Timing Lock Screw (Part 3904784) Compatibility with Cummins Engines

The Timing Lock Screw, identified by the part number 3904784, is a critical component in the timing mechanism of certain Cummins engines. This part is designed to secure the timing gear in place, ensuring that the engine’s timing remains consistent and accurate during operation.

Cummins 4B3.9 and 6B5.9 Engines

The 3904784 Timing Lock Screw is compatible with the Cummins 4B3.9 and 6B5.9 engines. These engines are part of the Cummins B Series, known for their reliability and performance in various applications. The timing lock screw plays a pivotal role in maintaining the precise timing required for these engines to operate efficiently.

Cummins QSB3.9 30 CM550 and QSB5.9 30 CM550 Engines

Similarly, the 3904784 Timing Lock Screw is also suitable for the Cummins QSB3.9 30 CM550 and QSB5.9 30 CM550 engines. These engines are part of the Cummins QSB Series, which is designed for heavy-duty applications. The timing lock screw ensures that the timing remains locked, preventing any misalignment that could lead to engine performance issues.

Grouping of Engines

The engines mentioned can be grouped based on their series and application:

• B Series: 4B3.9, 6B5.9
• QSB Series: QSB3.9 30 CM550, QSB5.9 30 CM550

Each series has its own set of applications, but the compatibility of the 3904784 Timing Lock Screw across these engines highlights its versatility and importance in maintaining engine timing.

Role of Part 3904784 Timing Lock Screw in Engine Systems

The Timing Lock Screw, identified as part 3904784, is integral to the synchronization and precise operation of various engine components. Its primary function is to secure the timing mechanism in place, ensuring that the rotational positions of the camshaft and crankshaft are accurately aligned. This alignment is essential for the proper functioning of the fuel injection system.

In engines equipped with a fuel injection pump, the Timing Lock Screw plays a significant role. It ensures that the fuel injection timing is consistent, allowing the fuel injection pump to deliver fuel at the exact moment required during the engine cycle. This precision is vital for optimal combustion efficiency and overall engine performance.

Similarly, in systems with a traditional fuel pump, the screw helps maintain the timing integrity, although the direct impact on fuel delivery might be less pronounced compared to fuel injection systems. Nevertheless, accurate timing is still necessary to ensure that the fuel is delivered in sync with the engine’s operational phases.

For engines utilizing a combined fuel and pump system, the Timing Lock Screw ensures that both the fuel delivery and pumping mechanisms are synchronized. This synchronization is essential for maintaining the correct fuel-air mixture, which is crucial for efficient combustion and reduced emissions.

Conclusion

In summary, the Timing Lock Screw (part 3904784) is a key component in ensuring that the timing mechanisms within the engine are accurately set. This, in turn, supports the efficient operation of fuel injection pumps, fuel pumps, and combined fuel and pump systems, contributing to the overall performance and reliability of the engine.