3937556
Belt Tensioner
Cummins®

The Cummins 3937556 Belt Tensioner is a component designed to maintain the proper tension on drive belts within commercial truck engines. Its role is significant in ensuring the efficient operation of various engine-driven accessories, such as alternators, water pumps, and air conditioning compressors ¹.

Basic Concepts of Belt Tensioners

A belt tensioner is a device used in an engine system to keep drive belts at the correct tension. It functions by applying consistent pressure to the belt, which prevents slippage and ensures that power is effectively transmitted from the engine to the accessories it drives. Maintaining proper belt tension is important for the longevity of the belts and the overall efficiency of the engine system ².

Purpose of the Cummins 3937556 Belt Tensioner

This Cummins part plays a role in the operation of a truck by maintaining the correct tension on drive belts. This ensures that the belts do not slip or become too tight, which could lead to premature wear or failure. By keeping the belts at the optimal tension, the tensioner contributes to the smooth and reliable operation of engine-driven accessories ³.

Key Features

The 3937556 is characterized by several key features that enhance its performance. Its design incorporates high-quality materials that are resistant to wear and corrosion, ensuring durability in demanding commercial truck environments. The tensioner is engineered to provide consistent belt tension under varying engine conditions, which is crucial for the reliable operation of engine accessories ⁴.

Benefits of Using the Cummins 3937556 Belt Tensioner

Utilizing this part offers several advantages. It contributes to improved engine efficiency by ensuring that drive belts operate at the optimal tension. This reduces the likelihood of belt slippage, which can lead to inefficient power transmission and increased wear on both the belts and the accessories they drive. Additionally, the tensioner enhances the reliability of the engine system by maintaining consistent belt tension, which is vital for the longevity of the belts and the accessories they support.

Installation Process

Installing the 3937556 involves several steps to ensure it is properly fitted and functions as intended. The process requires specific tools, such as a socket wrench and a tensioner tool, to securely fasten the tensioner and adjust the belt tension. It is important to follow the manufacturer’s instructions closely to avoid damaging the tensioner or the belts during installation.

Troubleshooting Common Issues

Common problems associated with belt tensioners include noise from the tensioner area, visible wear on the belt, or accessories not functioning properly. These issues can arise from improper installation, wear and tear on the tensioner, or incorrect belt tension. Addressing these problems may involve adjusting the tensioner, replacing worn belts, or, in some cases, replacing the tensioner itself to restore optimal performance.

Maintenance Tips

Maintaining the 3937556 involves regular inspection of the tensioner and the drive belts for signs of wear or damage. It is advisable to check the tensioner’s operation and the condition of the belts during routine engine maintenance. If signs of wear are detected, such as cracks in the belt or excessive noise from the tensioner, it may be necessary to consider replacement to prevent further issues.

Cummins: A Brief Overview

Cummins Inc. is a global power leader that designs, manufactures, and distributes engines, filtration, and power generation products. With a history of innovation and quality, Cummins has established a strong reputation in the commercial truck industry. The company’s product range includes a variety of engines and components designed to meet the demanding requirements of commercial applications, underscoring the quality and reliability of the 3937556 Belt Tensioner.

Belt Tensioner 3937556 Compatibility with Cummins Engines

The Belt Tensioner part number 3937556, manufactured by Cummins, is designed to fit a variety of Cummins engines. This part ensures that the engine’s belt system maintains proper tension, which is crucial for the efficient operation of the engine’s ancillary components such as the alternator, water pump, and air conditioning compressor.

Compatible Engines

• 4B3.9
• 6B5.9
• 6C8.3
• B5.9 G
• B5.9 GAS PLUS CM556
• B6.7S
• C GAS PLUS CM556
• C8.3 G
• ISB CM550
• QSB5.9 44 CM550
• QSB5.9 CM550

Grouping of Compatible Engines

The Belt Tensioner 3937556 is compatible with a range of Cummins engines, including both the B and QSB series. Here is a breakdown of the groupings:

• B Series Engines:

  • B5.9 G
  • B5.9 GAS PLUS CM556
  • B6.7S
  • C GAS PLUS CM556
  • C8.3 G

• QSB Series Engines:

  • QSB5.9 44 CM550
  • QSB5.9 CM550

• Other Compatible Engines:

  • 4B3.9
  • 6B5.9
  • 6C8.3
  • ISB CM550

This comprehensive compatibility ensures that the Belt Tensioner 3937556 can be used across a wide range of Cummins engines, providing a reliable solution for maintaining belt tension and ensuring optimal engine performance.

Role of Part 3937556 Belt Tensioner in Engine Systems

The part 3937556 Belt Tensioner is integral to maintaining the optimal operation of various engine components through its role in the belt drive system.

Interaction with Alternator Drive

The Belt Tensioner ensures that the belt driving the alternator is kept under the correct amount of tension. This is essential for the alternator to efficiently convert mechanical energy into electrical energy, which is then used to charge the battery and power the vehicle’s electrical systems.

Coordination with Drive Components

In the context of the drive system, the Belt Tensioner plays a key role in maintaining consistent belt tension across all driven components. This ensures smooth and efficient power transmission from the engine to auxiliary components.

Support for Alternator Functionality

By maintaining proper belt tension, the Belt Tensioner directly influences the alternator’s performance. A well-tensioned belt allows the alternator to spin at the correct speed, ensuring reliable electrical output and preventing issues such as undercharging or overcharging of the battery.

Engagement with Pulley Systems

The Belt Tensioner works in conjunction with the pulley system to ensure that belts are not too loose or too tight. This balance is vital for the longevity of the belts and the efficient operation of components like the alternator and water pump.

Contribution to Water Pump Drive

For the water pump drive, the Belt Tensioner ensures that the belt remains taut. This is important for the water pump to operate effectively, circulating coolant through the engine to maintain optimal temperature and prevent overheating.

Conclusion

In summary, the part 3937556 Belt Tensioner is a fundamental component in the belt drive system, ensuring that all connected engine components—such as the alternator, pulleys, and water pump—operate efficiently and reliably.