3900623
Hexagon Head Cap Screw
Cummins®

Introduction

The Hexagon Head Cap Screw, specifically part number 3900623 by Cummins, is a critical component in commercial truck maintenance. Cummins, a renowned manufacturer in the industry, produces this screw to withstand the demanding conditions of heavy-duty applications. Its role in maintaining the integrity and functionality of various truck components highlights its importance in the maintenance and operation of commercial vehicles.

Basic Concepts of Hexagon Head Cap Screw

A Hexagon Head Cap Screw is distinguished by its hexagonal head, which allows for efficient torque application using a wrench or socket. This design enables secure fastening and unfastening in mechanical assemblies. The screw’s threading engages with the internal threads of a nut or directly into a tapped hole, providing a strong and reliable connection. Its function is to hold components together under significant stress, ensuring structural integrity and operational efficiency ¹.

Purpose of the 3900623 Hexagon Head Cap Screw in Truck Operation

This Cummins part plays a role in the operation and maintenance of commercial trucks by securing various components. It is utilized in applications such as engine assemblies, chassis construction, and attachment of body panels. Its design ensures that these components remain firmly in place, contributing to the overall safety and performance of the vehicle ².

Key Features

The 3900623 Hexagon Head Cap Screw features a hexagonal head that provides a secure grip for tools, facilitating easy installation and removal. It is composed of high-strength materials, ensuring durability under heavy loads. The screw’s threading specifications are designed to offer a tight and secure fit, minimizing the risk of loosening over time.

Benefits

Utilizing this part offers several advantages. Its robust construction contributes to the longevity of the fastening, reducing the need for frequent replacements. The ease of installation enhances efficiency during maintenance procedures. Additionally, its resistance to loosening ensures that components remain securely fastened, even under dynamic operating conditions.

Installation Process

Proper installation of the 3900623 Hexagon Head Cap Screw involves several steps. Begin by ensuring the mating threads are clean and free of debris. Use the appropriate wrench or socket to drive the screw into the designated hole, applying even pressure to avoid cross-threading. Torque the screw to the manufacturer’s specified settings to ensure a secure fit without overtightening, which could damage the threads or the component being fastened ³.

Troubleshooting Common Issues

Common problems with Hexagon Head Cap Screws include loosening, corrosion, and damage to the head or threads. To address loosening, verify that the screw was properly torqued during installation and consider using a thread locker for additional security. Corrosion can be mitigated by selecting screws made from corrosion-resistant materials and applying protective coatings. Damaged screws should be replaced to maintain the integrity of the fastening.

Maintenance Tips

To ensure the longevity and optimal performance of the 3900623 Hexagon Head Cap Screw, periodic checks are recommended. Inspect the screw for signs of corrosion, loosening, or damage. Replace any screws that show signs of wear or failure. Additionally, applying a thread lubricant during installation can facilitate easier removal in the future and reduce the risk of galling.

Cummins: Manufacturer Overview

Cummins is a well-established manufacturer in the commercial truck industry, known for its comprehensive product range and commitment to quality. With a history of innovation and excellence, Cummins has earned a reputation for producing reliable and high-performance components. Their product lineup includes engines, powertrains, and aftermarket parts, all designed to meet the demanding requirements of commercial trucking.

Hexagon Head Cap Screw 3900623 in Cummins Engines

This Cummins part is a versatile component used across various Cummins engine models. This screw is integral in securing different parts and assemblies within the engine, ensuring structural integrity and operational efficiency.

Cummins 4B3.9 and QSB3.9 30 CM550

In the 4B3.9 and QSB3.9 30 CM550 engines, the 3900623 screw is often used in the cylinder head assembly, securing the head to the engine block. This ensures that the combustion chamber is properly sealed, which is crucial for maintaining engine performance and efficiency.

Cummins 6B5.9 and QSB4.5 CM2250 EC

For the 6B5.9 and QSB4.5 CM2250 EC engines, the 3900623 screw is frequently employed in the valve cover assembly. This application is critical for maintaining the seal between the valve cover and the engine block, preventing oil leaks and ensuring the smooth operation of the valve train.

Cummins 6C8.3 and C8.3 G

In the 6C8.3 and C8.3 G engines, the 3900623 screw is utilized in various applications, including securing the intake manifold to the engine block. This ensures that the intake system is properly sealed, which is essential for maintaining the correct air-fuel mixture and overall engine performance.

Cummins B4.5, B5.9 G, and B5.9 GAS PLUS CM556

For the B4.5, B5.9 G, and B5.9 GAS PLUS CM556 engines, the 3900623 screw is used in the fuel injection system. It helps secure various components of the fuel injection system, ensuring that the system operates correctly and efficiently.

Cummins C GAS PLUS CM556 and ISB CM550

In the C GAS PLUS CM556 and ISB CM550 engines, the 3900623 screw is used in the turbocharger assembly. This application is critical for securing the turbocharger to the engine, ensuring that it operates correctly and efficiently.

Cummins ISB5.9G CM2180, ISBE CM800, and ISL9 CM2150 SN

For the ISB5.9G CM2180, ISBE CM800, and ISL9 CM2150 SN engines, the 3900623 screw is used in the engine block assembly. It helps secure various components of the engine block, ensuring that the engine operates correctly and efficiently.

Cummins ISL9.5 CM2880 L138 and L8.9 CM2670 L134C

In the ISL9.5 CM2880 L138 and L8.9 CM2670 L134C engines, the 3900623 screw is used in the cylinder head assembly. This application is critical for securing the cylinder head to the engine block, ensuring that the combustion chamber is properly sealed.

Cummins K19, K38, and K50

For the K19, K38, and K50 engines, the 3900623 screw is used in the engine block assembly. It helps secure various components of the engine block, ensuring that the engine operates correctly and efficiently.

Cummins L8.9, L8.9 L121, L8.9G CMOH2.0 L125B, and L9.5 L117

In the L8.9, L8.9 L121, L8.9G CMOH2.0 L125B, and L9.5 L117 engines, the 3900623 screw is used in the engine block assembly. It helps secure various components of the engine block, ensuring that the engine operates correctly and efficiently.

Role of Part 3900623 Hexagon Head Cap Screw in Engine Systems

This part is integral to the secure assembly and operation of various engine components. Its applications span across multiple systems, ensuring the stability and efficiency of the engine.

Air Cleaner Mounting

In the air cleaner system, the Hexagon Head Cap Screw is used to mount the air cleaner assembly to the engine. This secure attachment ensures that the air cleaner remains in place, providing a consistent and clean air supply to the engine.

Alternator Location and Mounting

For the alternator, this screw plays a key role in securing the alternator to its designated location on the engine. Proper mounting is essential for the alternator’s function in generating electrical power, which is vital for the engine’s operation and the vehicle’s electrical systems.

Crankcase and Breather Systems

Within the crankcase and breather systems, the Hexagon Head Cap Screw is employed to attach covers and components. This ensures that the crankcase remains sealed, preventing oil leaks and maintaining the integrity of the engine’s lubrication system. Similarly, in the breather system, it helps in securing components that manage crankcase ventilation, which is important for engine performance and emissions control.

Fuel System Components

In the fuel system, particularly with components like the fuel pump coupling and injector test kit, the screw is used to secure connections and fittings. This is important for maintaining the fuel system’s integrity, ensuring consistent fuel delivery, and preventing leaks.

Engine Mounting and Bracket Kits

The screw is also crucial in engine mounting scenarios, such as securing the engine to the vehicle’s frame or mounting brackets like the M11 bracket kit. This application is important for the overall stability and alignment of the engine within the vehicle.

Noise Reduction and Vibration Damping

In systems designed for noise reduction and vibration damping, such as those involving dampers and vibration devices, the Hexagon Head Cap Screw is used to secure components. This helps in maintaining the effectiveness of these systems in reducing engine noise and vibrations, contributing to a smoother operation.

Exhaust and Plumbing Systems

Within the exhaust system and various plumbing connections, the screw is used to secure pipes, fittings, and other components. This ensures the integrity of the exhaust flow and the sealing of plumbing connections, which is important for engine performance and emissions.

Electronic Engine Control Systems

In electronic engine control systems, the screw is used to mount sensors, control units, and other electronic components. This secure attachment is important for the reliable operation of these systems, which are essential for modern engine management and performance optimization.

Conclusion

The Hexagon Head Cap Screw, part 3900623, plays a versatile and important role across various engine systems, contributing to the secure assembly, efficient operation, and overall performance of the engine. Its robust design and reliable functionality make it a critical component in the maintenance and operation of commercial trucks.