3900677
Hexagon Head Cap Screw
Cummins®

Understanding the Cummins 3900677 Hexagon Head Cap Screw

Introduction to Hexagon Head Cap Screws

Hexagon head cap screws, commonly known as hex bolts, are indispensable fasteners characterized by their hexagonal socket head, which necessitates a wrench or socket for installation and removal. These screws are extensively utilized across various industries due to their robust design and ability to provide secure connections. The hexagonal shape ensures efficient torque transfer, making them ideal for high-stress environments ¹.

Functionality of Hexagon Head Cap Screws

The primary function of a hexagon head cap screw is to thread into a tapped hole or onto a threaded part, with the hexagonal head offering a surface for a wrench or socket. This design facilitates precise tightening and allows for the application of significant torque without the risk of rounding off the head. The cap, or rounded top, serves to protect the screw from damage and provides a smooth surface that can interface with a washer or other mating surface ².

The Role of the Cummins 3900677 Hexagon Head Cap Screw in Truck Engines

The Cummins 3900677 hexagon head cap screw is engineered specifically for use in commercial truck engines. It is crucial for securing various engine components, ensuring that parts remain tightly fastened under the high stress and vibrations typical of engine operation. This screw is commonly used in applications where maintaining a precise and reliable connection is essential, such as fastening engine blocks, cylinder heads, and other critical assemblies ³.

Importance of Proper Installation and Maintenance

Proper installation of the Cummins 3900677 hexagon head cap screw is vital to ensure the integrity of the engine assembly. It is imperative to adhere to the correct torque specifications to prevent over-tightening, which can strip the threads or cause the screw to fail, or under-tightening, which can result in a loose connection and potential engine failure. Regular maintenance checks should be conducted to ensure that the screws remain tight and in good condition ¹.

Troubleshooting Common Issues

Common issues encountered with hexagon head cap screws include stripped threads, over-tightened screws, and corrosion. If a screw is found to be loose, it should be re-tightened to the correct torque specification. In cases where the threads are stripped, the affected screw should be replaced. To prevent corrosion, it is advisable to apply a protective coating or use stainless steel screws in environments where corrosion is a concern ².

Cummins: A Leader in Truck Engine Manufacturing

Cummins is a distinguished manufacturer of diesel engines, engine components, and related parts for the commercial truck market. With a legacy of innovation and quality, Cummins parts are engineered to meet the demanding requirements of heavy-duty applications. The Cummins 3900677 hexagon head cap screw exemplifies the company’s dedication to providing reliable and durable components for the commercial truck industry ³.

Expertise and Authority

As an expert in commercial truck parts, it is evident that the Cummins 3900677 hexagon head cap screw is a critical component in the operation of truck engines. Understanding its function, proper installation, and maintenance is essential for engineers, mechanics, truck drivers, and fleet operators to ensure the longevity and performance of their vehicles. Cummins’ reputation for quality and reliability further emphasizes the importance of using genuine parts in the maintenance and repair of commercial trucks.

Hexagon Head Cap Screw 3900677 Compatibility with Cummins Engines

The Cummins Hexagon Head Cap Screw part number 3900677 is a versatile component designed to fit a wide range of Cummins engines. This screw is integral in securing various parts within the engine assembly, ensuring structural integrity and operational efficiency. Below is a detailed breakdown of its compatibility across different Cummins engine models:

4B3.9 and 6B5.9 Engines

The 3900677 screw is compatible with the 4B3.9 and 6B5.9 engines, which are part of the B-Series family. These engines are known for their robust design and are often used in heavy-duty applications. The screw’s design ensures a secure fit, which is crucial for maintaining the alignment and stability of engine components.

B3.9 G, B4.5, and B4.5 CM2350 B129B Engines

The 3900677 screw also fits the B3.9 G, B4.5, and B4.5 CM2350 B129B engines. These engines are part of the B-Series and are widely used in various industrial and commercial applications. The screw’s precision threading and robust construction make it ideal for these engines, providing reliable fastening in demanding environments.

B4.5 RGT, B5.6 CM2670 B152B, and B5.9 CM2670 B166C Engines

The 3900677 screw is also compatible with the B4.5 RGT, B5.6 CM2670 B152B, and B5.9 CM2670 B166C engines. These engines are part of the B-Series and are known for their high performance and durability. The screw’s design ensures a tight and secure fit, which is essential for maintaining the integrity of the engine’s components under high stress.

B5.9 G, B5.9 GAS PLUS CM556, and B6.7 Engines

The 3900677 screw is also suitable for the B5.9 G, B5.9 GAS PLUS CM556, and B6.7 engines. These engines are part of the B-Series and are used in a variety of applications, from industrial to commercial. The screw’s high-strength properties ensure that it can withstand the rigors of these engines, providing reliable fastening and stability.

B6.7 CM2350 B135B, B6.7 CM2670 B153B, and B6.7 CM2670 B164C Engines

The 3900677 screw is also compatible with the B6.7 CM2350 B135B, B6.7 CM2670 B153B, and B6.7 CM2670 B164C engines. These engines are part of the B-Series and are known for their efficiency and reliability. The screw’s precision engineering ensures a perfect fit, which is crucial for maintaining the alignment and performance of the engine’s components.

B6.7 G CMOH6.0 B125, C GAS PLUS CM556, G5.9, and G5.9 CM558 Engines

The 3900677 screw is also suitable for the B6.7 G CMOH6.0 B125, C GAS PLUS CM556, G5.9, and G5.9 CM558 engines. These engines are part of the C-Series and are used in various applications, from industrial to commercial. The screw’s robust design ensures a secure fit, which is essential for maintaining the integrity of the engine’s components under high stress.

C8.3 G, F3.8 CM2350 F128C, F4.5 CM2620 F141C, G8.3, and G8.3 CM558 Engines

The 3900677 screw is also compatible with the C8.3 G, F3.8 CM2350 F128C, F4.5 CM2620 F141C, G8.3, and G8.3 CM558 engines. These engines are part of the C-Series and are known for their high performance and durability. The screw’s precision threading and robust construction make it ideal for these engines, providing reliable fastening in demanding environments.

G855 and GTA8.3 CM558 Engines

Finally, the 3900677 screw is also suitable for the G855 and GTA8.3 CM558 engines. These engines are part of the G-Series and are used in a variety of applications, from industrial to commercial. The screw’s high-strength properties ensure that it can withstand the rigors of these engines, providing reliable fastening and stability.

In summary, the Cummins Hexagon Head Cap Screw part number 3900677 is a versatile and reliable component that is compatible with a wide range of Cummins engines. Its precision engineering and robust design ensure a secure fit, which is essential for maintaining the integrity and performance of the engine’s components.

Role of Part 3900677 Hexagon Head Cap Screw in Engine Systems

The 3900677 Hexagon Head Cap Screw is integral to the assembly and securement of various components within engine systems. It ensures the stability and integrity of connections, allowing the engine to function efficiently.

Air Intake Connection

In the air intake system, the 3900677 screw is used to fasten components such as the air intake manifold to the engine block. This securement is vital for maintaining airtight seals, which are necessary for optimal airflow into the combustion chambers.

Alternator Location

At the alternator location, the screw plays a role in attaching the alternator to the engine block or mounting bracket. This ensures the alternator remains firmly in place, allowing it to generate electricity reliably without vibrations that could lead to failure.

Engine Blocks

Across various engine blocks, including the Block 6-B Short, Block Short 6-BT, Block Short 6BT, Block Short E2 Incent, and Block Short Euro1, the 3900677 screw is employed to secure ancillary components. These may include sensor mounts, bracketry for auxiliary systems, and other attachments that require a robust fastening solution.

Centrifugal Oil Filter

In the centrifugal oil filter assembly, the screw is used to secure the filter housing to the engine block. This ensures that the oil filter is correctly positioned and sealed, allowing for effective filtration of contaminants from the engine oil.

Clutch and Cylinder Head

For the rear clutch and cylinder head, the 3900677 screw is utilized to fasten cover plates, gaskets, and other components. This securement is essential for maintaining the structural integrity of these critical engine parts.

Flexible Coupling and Fuel System

In the fuel system, particularly in fuel filter and fuel plumbing components, the screw ensures that connections are tight and leak-free. This is important for maintaining fuel pressure and preventing fuel leaks, which could pose safety hazards.

Lubricating Oil Pump and Plumbing

The screw is also instrumental in securing the lubricating oil pump and its associated plumbing. Proper securement ensures that the oil pump can deliver lubricant efficiently throughout the engine, reducing wear and tear on moving parts.

Exhaust Recirculation Air and Plumbing

In the exhaust recirculation system, the screw is used to fasten components such as the exhaust recirculation air valve and associated plumbing. This ensures that the recirculation process is effective in reducing emissions.

Rocker Lever Top Level Assembly Cover

The screw secures the rocker lever top-level assembly cover, ensuring that the cover remains in place and provides necessary protection for the rocker arms and other components within.

Torque Converter Cooler

Finally, in the torque converter cooler system, the screw is used to attach the cooler to the engine or transmission. This ensures that the cooler remains securely in place, allowing it to effectively dissipate heat from the transmission fluid.