118312
Head Locking Screw
Cummins®

Introduction

The Cummins 118312 Head Locking Screw is a specialized fastener designed for use in heavy-duty truck engines. Its primary role is to secure the cylinder head to the engine block, ensuring a proper seal and alignment. This component is integral to maintaining the integrity of the engine’s combustion chamber and overall performance ¹.

Purpose and Function

The Cummins 118312 Head Locking Screw serves to fasten the cylinder head to the engine block. This secure attachment is vital for maintaining the seal between the head and block, which is necessary for proper engine function. The screw ensures that the cylinder head remains in the correct position, allowing for efficient combustion and preventing leaks that could compromise engine performance ².

Design and Construction

The Cummins 118312 Head Locking Screw is crafted from high-strength materials to withstand the rigorous conditions within a heavy-duty engine. It features a specific thread type designed for optimal engagement with the engine block. The screw may also include special coatings or treatments to enhance corrosion resistance and durability. These design elements contribute to the screw’s ability to maintain a secure and lasting connection ³.

Installation Process

Proper installation of the Cummins 118312 Head Locking Screw is critical for engine performance. The process involves threading the screw into the engine block and tightening it to the manufacturer’s specified torque. This ensures that the cylinder head is held firmly in place without over-tightening, which could damage the threads or warp the head. Following recommended practices during installation helps to achieve the desired sealing and alignment ⁴.

Benefits

The use of the Cummins 118312 Head Locking Screw offers several advantages. It contributes to enhanced engine performance by ensuring a secure and proper seal between the cylinder head and engine block. This results in improved combustion efficiency and reduced risk of leaks. Additionally, the screw’s robust design and materials promote reliability and longevity, supporting the overall durability of the engine ¹.

Common Issues and Troubleshooting

Typical problems associated with head locking screws include loosening over time, corrosion, and thread damage. These issues can lead to leaks and reduced engine efficiency. Diagnostic tips include regular inspection for signs of wear or corrosion and ensuring that the screw is properly torqued. Recommended solutions may involve re-torquing the screw, applying anti-seize compound, or replacing the screw if damage is detected ².

Maintenance and Inspection

Routine maintenance and inspection of the Cummins 118312 Head Locking Screw are important for preventing potential failures. This includes checking for signs of wear, corrosion, or loosening during regular engine servicing. Ensuring that the screw remains properly torqued and in good condition helps to maintain optimal engine performance and prevent issues related to improper sealing or alignment ³.

Manufacturer Overview

Cummins Inc. is a leading manufacturer in the automotive industry, known for its high-quality engines and components. With a rich history and a diverse product portfolio, Cummins has established a strong reputation for reliability and performance. The company’s commitment to innovation and excellence is reflected in its range of engine parts, including the Cummins 118312 Head Locking Screw ⁴.

Compatibility with Cummins Engines

The Cummins part 118312, a Head Locking Screw, is compatible with various Cummins engine models. This screw is designed to securely fasten the cylinder head to the engine block, ensuring a tight seal and preventing any movement that could lead to engine failure.

ISM Series Engines

• ISM CM570
• ISM CM570/870
• ISM CM876

K Series Engines

• K19
• K38
• K50

L10 Series Engines

• L10 CELECT
• L10 GAS
• L10 MECHANICAL

M11 Series Engines

• M11 CELECT
• M11 CELECT PLUS
• M11 MECHANICAL

N14 Series Engines

• N14 CELECT
• N14 CELECT PLUS
• N14 MECHANICAL

NH/NT 855

QSK Series Engines

• QSK19 CM2350 K114
• QSK19 CM500
• QSK19 CM850 MCRS
• QSK38 CM2150 MCRS
• QSK45 CM500
• QSK50 CM2150 MCRS
• QSK50 CM2350 K108

QSM11 CM570

QST30 CM2350 T101

Role of Part 118312 Head Locking Screw in Engine Systems

The Part 118312 Head Locking Screw is integral to the secure assembly and operation of various engine components. It ensures that the head of the engine is firmly attached, preventing any unwanted movement that could lead to engine malfunction.

Flexplate Assembly

In the Flexplate Assembly, the Head Locking Screw plays a significant role in maintaining the integrity of the connection between the engine and the transmission. This assembly often includes the Flexplate and Flexplate Assy, where the screw ensures that all components are tightly secured. Proper fastening is essential to prevent any slippage or misalignment that could affect the transmission of power from the engine to the drivetrain.

Flex Disc Drive

When integrated with the Flex Disc Drive, the Head Locking Screw helps in securing the flex disc to the flexplate. This is vital for smooth power transmission, as any looseness can result in vibrations or uneven power delivery to the wheels. The screw ensures that the flex disc remains in the correct position, contributing to the overall efficiency and reliability of the drivetrain.

Flywheel

In systems that utilize a Flywheel, the Head Locking Screw is used to secure the flywheel to the engine crankshaft. This is important for storing rotational energy and smoothing out the power delivery to the transmission. A securely fastened flywheel ensures consistent engine performance and reduces the risk of mechanical failures.

Flexplate Kit

The Flexplate Kit often includes multiple components such as the Flexplate and Flexplate Assy. The Head Locking Screw is used throughout this kit to ensure that all parts are correctly and firmly attached. This comprehensive fastening is essential for the kit’s functionality, as it ensures that the flexplate can withstand the stresses of engine operation without any component shifting or failing.

Conclusion

Understanding the role of the Cummins 118312 Head Locking Screw in these engine components is essential for engineers and mechanics to ensure that their assemblies are secure and operate efficiently, leading to better overall engine performance.