3950661
Connecting Rod Bearing
Cummins®

The Cummins 3950661 Connecting Rod Bearing is a specialized component designed for use in heavy-duty truck engines. Its purpose is to facilitate the smooth operation of the engine by reducing friction between the connecting rod and the crankshaft. This bearing plays a significant role in maintaining the efficiency and durability of the engine, ensuring reliable performance under demanding conditions ¹.

Basic Concepts of Connecting Rod Bearings

Connecting rod bearings are integral components within an engine, designed to support the connecting rod’s movement as it connects the piston to the crankshaft. These bearings operate by providing a low-friction surface that allows the connecting rod to pivot smoothly around the crankshaft journal. This smooth operation is vital for the engine’s overall performance, as it helps to maintain consistent power delivery and reduces wear on engine components ².

Role of the 3950661 Connecting Rod Bearing in Truck Operation

The Cummins 3950661 Connecting Rod Bearing specifically contributes to the operation of heavy-duty truck engines by ensuring that the connecting rod moves efficiently around the crankshaft. This bearing helps to minimize friction, which in turn reduces heat generation and wear on the engine components. By maintaining smooth operation, the 3950661 bearing supports the engine’s efficiency and longevity, allowing heavy-duty trucks to perform reliably even under strenuous conditions ³.

Key Features

The Cummins 3950661 Connecting Rod Bearing is characterized by several key features that enhance its performance and durability. These include a precision-engineered design that ensures a perfect fit within the engine, high-quality materials that resist wear and corrosion, and advanced manufacturing techniques that guarantee consistent quality. Additionally, the bearing’s unique attributes, such as its load-bearing capacity and resistance to fatigue, contribute to its superior performance in heavy-duty applications ⁴.

Benefits

Using the Cummins 3950661 Connecting Rod Bearing offers several benefits. These include improved engine performance due to reduced friction, which leads to more efficient power transmission. The bearing’s design also contributes to enhanced durability, helping to extend the engine’s service life. Furthermore, the reduced wear and maintenance requirements associated with this bearing can result in potential cost savings over time, making it a valuable component for heavy-duty truck operators ⁵.

Troubleshooting and Maintenance

Common issues that may arise with connecting rod bearings include excessive wear, noise, or failure due to contamination or improper lubrication. To ensure optimal performance, regular maintenance practices should be followed, such as monitoring oil quality and levels, inspecting bearing surfaces for signs of wear, and adhering to manufacturer-recommended service intervals. Troubleshooting tips include listening for unusual noises, checking for oil leaks, and performing diagnostic tests to identify any issues promptly ⁶.

About Cummins

Cummins Inc. is a global power leader that designs, manufactures, and distributes engines, filtration, and power generation products. With a strong reputation in the industry, Cummins is known for its commitment to producing high-quality automotive components that meet the demanding requirements of heavy-duty applications. The company’s history of innovation and excellence underscores its dedication to providing reliable and efficient solutions for its customers ⁷.

Compatibility of 3950661 with Cummins Engines

The Cummins Connecting Rod Bearing part number 3950661 is designed to fit a variety of Cummins engines, providing essential support and reducing friction between the connecting rod and crankshaft. Here is a detailed look at the compatibility of this part with various Cummins engines:

ISC Series Engines

• ISC CM2150
• ISC CM554
• ISC CM850
• ISC8.3 CM2250

ISL Series Engines

• ISL CM2150
• ISL CM554
• ISL G CM2180
• ISL9 CM2150 SN
• ISL9 CM2250
• ISL9.5 CM2880 L138

L Series Engines

• L GAS PLUS CM556
• L8.9
• L8.9 CM2670 L134C
• L8.9 L121
• L8.9G CMOH2.0 L125B
• L9 CM2670 L128B
• L9.3 L105
• L9.5 L117

G Series Engines

• G8.3
• G8.3 CM558
• GTA8.3 CM558
• QSC8.3 CM2880 C102

C Series Engines

• C GAS PLUS CM556

By ensuring that the 3950661 Connecting Rod Bearing is used with the appropriate Cummins engine, you can maintain optimal engine performance and longevity ⁸.

Role of Part 3950661 in Engine Systems

The Connecting Rod Bearing (Part 3950661) is an essential component in the efficient operation of various engine systems. It facilitates smooth interaction between the connecting rod and the cylinder block, reducing friction and wear.

When integrated into an engine assembly, the connecting rod bearing ensures that the connecting rod can pivot with minimal resistance as the piston moves up and down. This is particularly important in high-performance engines where precision and efficiency are paramount.

In a short block or long block configuration, the connecting rod bearing plays a significant role in maintaining the integrity of the engine’s moving parts. It allows the connecting rod to transmit the piston’s linear motion to the crankshaft effectively, which is vital for the engine’s power output.

During an engine overhaul or when using an overhaul kit, replacing the connecting rod bearings is often necessary to restore the engine’s performance to factory specifications. This is also true when utilizing a rebuild kit or repair kit, where worn-out bearings can be a common point of failure.

In conjunction with a piston engine kit or engine piston kit, the connecting rod bearing ensures that the piston’s movement is translated into rotational force without excessive wear on the crankshaft journals. This is especially important in high-rpm applications where the connecting rod experiences significant stress.

When paired with performance parts or a PMM piston upgrade, the connecting rod bearing must be of high quality to handle increased loads and stresses. This is essential for maintaining engine reliability and performance under demanding conditions.

The connecting rod bearing also interacts with the camshaft indirectly, as the smooth operation of the piston and connecting rod assembly contributes to the overall harmony of the engine’s valve timing and combustion efficiency.

Conclusion

In summary, the Cummins 3950661 Connecting Rod Bearing is a fundamental component that ensures the smooth and efficient operation of the engine’s moving parts, contributing to the overall performance and longevity of the engine system. Its precision-engineered design, high-quality materials, and compatibility with various Cummins engines make it an indispensable part for heavy-duty applications.