3939859
Connecting Rod (STUD) Bearing
Cummins®

Introduction

The Cummins 3939859 Connecting Rod (STUD) Bearing is a specialized component designed for use in commercial truck engines. Its purpose is to facilitate the smooth operation of the engine by enabling efficient power transfer from the piston to the crankshaft. This bearing plays a role in maintaining the engine’s performance and durability, ensuring reliable operation under demanding conditions.

Basic Concepts of Connecting Rod (STUD) Bearings

Connecting rod bearings are components within an engine, positioned between the crankshaft and the connecting rod. Their primary function is to reduce friction and wear between these moving parts, allowing for smooth and efficient power transmission. By minimizing friction, these bearings contribute to the overall performance and longevity of the engine ¹.

Purpose of the 3939859 Connecting Rod (STUD) Bearing

The 3939859 Connecting Rod (STUD) Bearing serves a role in the operation of a truck engine. It facilitates the connection between the crankshaft and the piston, enabling the efficient transfer of power generated by the combustion process. This bearing ensures that the reciprocating motion of the piston is smoothly converted into rotational motion of the crankshaft, which is important for the engine’s operation.

Key Features

The 3939859 Connecting Rod (STUD) Bearing is characterized by several key features that enhance its performance and reliability. Its design incorporates high-quality materials that provide superior strength and durability. The bearing is engineered to withstand the high loads and stresses encountered in commercial truck engines, ensuring consistent performance over time. Additionally, its precise manufacturing tolerances contribute to reduced friction and wear, further enhancing engine efficiency.

Benefits

The advantages of the 3939859 Connecting Rod (STUD) Bearing include improved engine efficiency, reduced friction, and enhanced durability. By minimizing friction between the crankshaft and connecting rod, this bearing helps to increase engine efficiency and reduce wear on these critical components. Its robust construction contributes to the overall longevity of the engine, making it a reliable choice for commercial truck applications.

Installation and Maintenance

Proper installation and maintenance of the 3939859 Connecting Rod (STUD) Bearing are important for ensuring optimal performance. Installation should follow manufacturer guidelines, using the appropriate tools and procedures to ensure a secure fit. Routine maintenance checks, including inspections for wear and proper lubrication, are recommended to prevent issues and ensure the bearing continues to operate efficiently.

Troubleshooting Common Issues

Common problems associated with connecting rod bearings can include excessive wear, noise, or failure. These issues may be caused by factors such as inadequate lubrication, misalignment, or excessive load. Troubleshooting steps may involve inspecting the bearing for signs of wear, checking lubrication levels, and ensuring proper alignment and fit within the engine.

Performance Enhancements

The 3939859 Connecting Rod (STUD) Bearing can contribute to performance enhancements in commercial truck engines. By reducing friction and wear, it helps to improve power output and fuel efficiency. Its durable construction also enhances the reliability of the engine, allowing for consistent performance under demanding conditions.

Cummins: A Brief Overview

Cummins Inc. is a leading manufacturer of diesel engines, known for its commitment to quality and innovation in the commercial truck industry. With a diverse product range and a reputation for reliability, Cummins engines are widely used in various applications, including heavy-duty trucks. The 3939859 Connecting Rod (STUD) Bearing is part of Cummins’ extensive lineup of high-quality engine components, designed to meet the demanding requirements of commercial truck engines.

Cummins Connecting Rod (STUD) Bearing 3939859 Compatibility

The Cummins Connecting Rod (STUD) Bearing part number 3939859 is designed to fit a variety of Cummins engines, ensuring compatibility and reliability across different engine models. Here’s how this part fits with the specified engines:

ISB Series Engines

• ISB CM2150
• ISB CM550
• ISB CM850
• ISB5.9 CM2880 B110

The ISB series engines, including the ISB CM2150, ISB CM550, ISB CM850, and ISB5.9 CM2880 B110, are compatible with the 3939859 Connecting Rod (STUD) Bearing. This part is engineered to provide optimal performance and durability for these engines.

ISBE Series Engines

• ISBE CM800
• ISBE4 CM850

The ISBE series engines, such as the ISBE CM800 and ISBE4 CM850, also utilize the 3939859 Connecting Rod (STUD) Bearing. This bearing is specifically designed to meet the requirements of these engines, ensuring smooth operation and longevity.

ISF Series Engines

• ISF3.8 CM2220 AN

The ISF3.8 CM2220 AN engine is another model that is compatible with the 3939859 Connecting Rod (STUD) Bearing. This part is important for maintaining the structural integrity and performance of the engine.

QSB Series Engines

• QSB3.9 30 CM550
• QSB4.5 CM850(CM2850)
• QSB5.9 30 CM550
• QSB5.9 44 CM550
• QSB5.9 CM2880 B115
• QSB5.9 CM850
• QSB6.7 CM850(CM2850)
• QSB7 CM2880 B117

The QSB series engines, including the QSB3.9 30 CM550, QSB4.5 CM850(CM2850), QSB5.9 30 CM550, QSB5.9 44 CM550, QSB5.9 CM2880 B115, QSB5.9 CM850, QSB6.7 CM850(CM2850), and QSB7 CM2880 B117, are all compatible with the 3939859 Connecting Rod (STUD) Bearing. This bearing is designed to fit seamlessly into these engines, providing the necessary support and reducing wear and tear.

Other Cummins Engines

• 4B3.9
• 6B5.9
• B3.3

The 3939859 Connecting Rod (STUD) Bearing is also suitable for other Cummins engines such as the 4B3.9, 6B5.9, and B3.3. This part ensures that these engines operate efficiently and reliably.

By ensuring compatibility with a wide range of Cummins engines, the 3939859 Connecting Rod (STUD) Bearing provides a versatile and reliable solution for maintaining engine performance and longevity.

Role of Part 3939859 Connecting Rod (STUD) Bearing in Engine Systems

The Part 3939859 Connecting Rod (STUD) Bearing is a component in the efficient operation of various engine systems. This bearing facilitates the smooth rotation of the connecting rod around the crankshaft journal, minimizing friction and wear.

In the Short Block configurations, such as the Short 4BTA Block, Short 6-BT Block, Short 6BT Block, Short E2 Incent Block, Short Euro1 Block, Short 6-B Block, Short E1 180 Block, Short E2 Block, and Short E215/235 Block, the connecting rod bearing ensures that the reciprocating motion of the piston is effectively translated into rotational motion of the crankshaft. This is vital for maintaining engine balance and performance.

When integrated with the Connecting Rod and Piston assembly, the bearing allows for precise alignment and movement, which is necessary for the efficient transfer of power from the piston to the crankshaft. The Engine Piston relies on the smooth operation of this bearing to maintain consistent compression and combustion cycles.

In Long Block assemblies, which include the cylinder block, pistons, and often the camshaft, the connecting rod bearing plays a role in ensuring that all moving parts operate in harmony. The Camshaft, which controls the opening and closing of the valves, depends on the consistent and smooth operation of the crankshaft, which in turn relies on the efficient functioning of the connecting rod bearings.

For Pistonless Overhaul scenarios, where the engine block is retained but the pistons and related components are replaced, the connecting rod bearing is crucial for re-establishing the necessary mechanical linkages and ensuring that the new pistons operate smoothly within the engine.

In Overhaul Kits and Performance Parts, the connecting rod bearing is often included to enhance the durability and performance of the engine. These kits may also contain Injector Plumbing and Injector components, where the efficient operation of the connecting rod bearing contributes to the overall reliability of the fuel delivery system.

The Rod Bearing Set and Connection Rod Bearing Kit are specifically designed to provide comprehensive support for the connecting rod, ensuring that it can withstand the high loads and stresses encountered during engine operation.

Conclusion

In summary, the Part 3939859 Connecting Rod (STUD) Bearing is a fundamental component that ensures the smooth and efficient operation of various engine systems, from short blocks to long blocks, and is integral to the performance and longevity of the engine.