3678873
Threaded Plug
Cummins®

The Cummins 3678873 Threaded Plug is a component designed for use in commercial trucks. Its primary role is to seal openings within the truck’s system, preventing fluid leaks and maintaining the integrity of the system. This part is specifically engineered to meet the demanding requirements of heavy-duty applications, ensuring reliable performance in various operating conditions.

Basic Concepts of Threaded Plugs

Threaded plugs are mechanical devices used to seal threaded openings in various systems. They function by creating a tight seal that prevents the escape of fluids or gases. In automotive applications, threaded plugs are commonly used in engine blocks, transmission cases, and other components where sealing is necessary. These plugs are typically constructed from materials such as brass, steel, or aluminum, chosen for their durability and resistance to corrosion. Standard threading types include UNF (Unified National Fine) and UNC (Unified National Coarse), which ensure compatibility with a wide range of applications ¹.

Purpose and Function of the 3678873 Threaded Plug

The Cummins 3678873 Threaded Plug serves a specific role in a truck’s system by sealing openings that may otherwise allow fluids to leak. This plug helps maintain system pressure and prevents contaminants from entering the system. By ensuring a secure seal, it contributes to the overall efficiency and reliability of the truck’s operation ².

Key Features

The Cummins 3678873 Threaded Plug is characterized by several key features that enhance its performance and durability. Its design includes precise threading specifications to ensure a tight fit within the designated openings. The material composition is selected to withstand high-stress conditions commonly encountered in commercial truck applications. Additionally, the plug may feature unique attributes such as a corrosion-resistant coating or enhanced sealing properties to further improve its functionality.

Benefits

Using the Cummins 3678873 Threaded Plug offers several advantages. Its design contributes to improved sealing efficiency, reducing the risk of fluid leaks. The plug’s durability ensures it can withstand the rigors of heavy-duty use, providing long-term reliability. Furthermore, its compatibility with Cummins engines ensures seamless integration into the truck’s system, maintaining optimal performance.

Troubleshooting and Maintenance

Common issues associated with threaded plugs include leaks due to wear or damage and difficulty in removal due to corrosion. Diagnosing problems involves inspecting the plug for signs of wear, corrosion, or damage. Regular maintenance practices, such as cleaning the threading and applying a light coating of lubricant, can help ensure the plug’s longevity and proper function. When replacement is necessary, it is important to follow proper procedures to avoid damaging the threading or surrounding components.

Compatibility with Cummins Engines

The Cummins Threaded Plug part number 3678873 is designed to fit a variety of Cummins engines, ensuring compatibility across multiple models. Here is a detailed breakdown of the engines with which this part is compatible:

M104B Series

• 15N CM2380 M104B

6C8.3 Series

• 6C8.3

B4.5 RGT Series

• B4.5 RGT

B6.7 Series

• B6.7 CM2350 B135B
• B6.7 CM2670 B153B
• B6.7 CM2670 B164C
• B6.7 G CMOH6.0 B125
• B6.7S
• B6.7 CM2150
• B6.7 CM850
• B6.7/ISD4.5 CM2150 B119
• B6.7/ISD6.7 CM2150 SN
• B6.7 CM2350 B101
• B6.7 G CM2180 B118

F4.5 Series

• F4.5 CM2620 F139B

G855 Series

• G855
• G855 CM558

GTA Series

• GTA38 G CMEICS G116C
• GTA855 CM558 (CM2358) G101

ISB Series

• ISB (Chrysler)
• ISB CM2150
• ISB CM850
• ISB/ISD4.5 CM2150 B119
• ISB/ISD6.7 CM2150 SN
• ISB4.5 CM2350 B104
• ISB6.7 CM2250
• ISB6.7 CM2350 B101
• ISB6.7 G CM2180 B118
• ISBE CM2150
• ISBE CM800
• ISBE4 CM850

This threaded plug is engineered to meet the specific needs of these engines, ensuring a secure and reliable fit. It is crucial to verify the compatibility of this part with the specific engine model before installation to ensure optimal performance and safety ³.

Role of Part 3678873 Threaded Plug in Engine Systems

The Cummins 3678873 Threaded Plug is integral to the functionality and maintenance of various engine systems. It is commonly used to seal openings in components, ensuring the integrity of the system it is installed in.

In the alternative design of engine components, the threaded plug is often utilized to seal off passages that are not required in a particular configuration, allowing for flexibility in engine design without the need for completely different parts.

For the auxiliary cooling system, it plays a role in sealing off coolant passages that may not be in use, ensuring that the coolant flow is directed efficiently through the active parts of the system.

In the context of the connecting rod and piston assembly, the threaded plug may be used to seal oil passages or to plug threaded holes that are not in use, maintaining the proper lubrication and operation of these critical moving parts.

When it comes to the crankshaft and bearings, the threaded plug is employed to seal off lubrication passages or to cover threaded holes that are not utilized, contributing to the smooth operation and longevity of the crankshaft.

For the cylinder block hardware kit and cylinder block kit, the threaded plug is essential for sealing various openings within the block, ensuring that coolant, oil, and other fluids are correctly channeled and do not leak.

In the engine coolant assembly vent and engine coolant vent, the threaded plug is used to seal off vent passages when they are not required, maintaining the pressure and flow of the coolant system.

With exhaust recirculation systems, the plug may be used to seal off passages that are not part of the active recirculation path, ensuring that exhaust gases are correctly rerouted for emission control.

In the front gear housing, the threaded plug is utilized to seal off oil passages or plug threaded holes, ensuring the housing maintains its structural integrity and proper function.

For the fuel control and fuel control housing, the plug is used to seal off fuel passages that are not in use, ensuring the fuel system operates efficiently and safely.

At the fuel filter location, the threaded plug may be used to seal the filter housing when the filter is being changed or when the system is being serviced.

In the fuel injection pump, the plug is used to seal off passages that are not active, ensuring the pump operates with precision and efficiency.

Within the fuel system, the threaded plug is employed to seal off fuel lines or passages that are not in use, maintaining the system’s integrity and performance.

For the lubricating oil assembly filter and lubricating oil cooler module, the plug is used to seal off oil passages, ensuring the lubrication system functions correctly and maintains the engine’s moving parts.

In the oil bypass filter and oil pan, the threaded plug is utilized to seal off passages or plug threaded holes, ensuring the oil system remains sealed and operates efficiently.

For the oil top level assembly pan, the plug is used to seal off openings that are not required, maintaining the correct oil level and system integrity.

In performance parts, the threaded plug may be used to seal off passages that are not utilized in a particular performance configuration, allowing for customization and optimization of engine performance.

On the rocker lever, the plug is used to seal off oil passages or plug threaded holes, ensuring the rocker lever operates smoothly and is properly lubricated.

In the short block, the threaded plug is essential for sealing various openings within the block, ensuring that coolant, oil, and other fluids are correctly channeled.

For the turbocharger kit and turbocharger leak test kit, the plug is used to seal off passages that are not in use during testing or when certain functions are not required, ensuring the turbocharger operates efficiently and is correctly sealed.

Conclusion

The Cummins 3678873 Threaded Plug is a vital component in ensuring the integrity and efficiency of various engine systems. Its design and features contribute to reliable sealing, preventing fluid leaks and maintaining system pressure. Regular maintenance and proper installation are essential to maximize the benefits of this part, ensuring the longevity and optimal performance of commercial truck engines.