5521188
Flexplate
Cummins®

Introduction

The Cummins 5521188 Flexplate is a component designed for use in heavy-duty trucks equipped with automatic transmissions. Its primary function is to connect the engine to the transmission, facilitating the transfer of power from the engine to the drivetrain. This part is integral to the smooth operation of the vehicle, ensuring efficient power transmission and contributing to the overall performance and reliability of the truck ¹.

Basic Concepts of Flexplates

A flexplate is a component in the drivetrain of vehicles with automatic transmissions. It serves a similar purpose to a flywheel in manual transmission vehicles but is designed to be more flexible. The flexplate is mounted to the front of the engine and connects to the torque converter, which is part of the transmission. Unlike a flywheel, which is solid and heavy, a flexplate is typically made from a stamped steel disc with a series of starter ring gear teeth around its perimeter. This design allows it to flex slightly, accommodating the varying loads and stresses encountered in automatic transmissions ².

Role of the 5521188 Flexplate in Truck Operation

The Cummins 5521188 Flexplate plays a role in the operation of heavy-duty trucks by serving as the interface between the engine and the transmission. It is responsible for transmitting the rotational force (torque) generated by the engine to the torque converter, which then transfers this power to the transmission and ultimately to the wheels. The flexplate’s design allows it to absorb and dampen the vibrations and shocks that occur during operation, contributing to a smoother and more efficient power transfer ³.

Key Features

The Cummins 5521188 Flexplate is characterized by several key features that enhance its performance and durability. It is constructed from high-strength materials, ensuring it can withstand the high torque and stress levels typical of heavy-duty applications. The flexplate’s design includes a series of starter ring gear teeth, which engage with the starter motor to crank the engine during startup. Additionally, the flexplate is engineered to provide optimal balance and minimal flex, which helps in reducing wear and tear on the transmission and improving overall efficiency ⁴.

Benefits

The Cummins 5521188 Flexplate offers several benefits in heavy-duty truck applications. Its robust construction and design contribute to improved durability, allowing it to withstand the demanding conditions of heavy-duty use. The flexplate’s ability to absorb vibrations and shocks leads to smoother operation and reduced stress on the transmission components. Furthermore, its efficient design helps in enhancing the overall performance and fuel efficiency of the truck ⁵.

Troubleshooting and Maintenance

To ensure the longevity and optimal performance of the Cummins 5521188 Flexplate, regular maintenance and troubleshooting are recommended. Common issues may include wear on the starter ring gear teeth, which can affect the engine’s starting capability, or cracks in the flexplate due to stress or fatigue. Regular inspections for signs of wear, such as chipped or missing teeth, and checking for any cracks or deformations, are important maintenance practices. Additionally, ensuring proper torque when installing or replacing the flexplate can help prevent future issues ⁶.

Compatibility with Cummins Engines

The Cummins 5521188 Flexplate is designed to fit a variety of Cummins engines. This part is crucial for the proper functioning of the engine’s torque converter and the transmission system. Below is a detailed description of the compatibility of this flexplate with different Cummins engines.

ISB Series Engines

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

The Flexplate 5521188 is compatible with all ISB series engines. This includes various configurations such as ISB, ISD, and ISBE engines, with different displacements and configurations. The flexplate ensures a smooth connection between the engine and the transmission, facilitating efficient power transfer.

QSB Series Engines

• QSB4.5 CM2250 EC
• QSB4.5 CM850(CM2850)
• QSB6.7 CM2250
• QSB6.7 CM2350 B105
• QSB6.7 CM850(CM2850)
• QSB7 CM2880 B117

The Flexplate 5521188 is also compatible with the QSB series engines. This includes both 4.5L and 6.7L engines, with various configurations and displacements. The flexplate ensures that the torque converter and transmission are properly aligned with the engine, providing a seamless power transfer.

Other Cummins Engines

• 4B3.9
• 6B5.9
• B5.9 G
• B5.9 GAS PLUS CM556
• F3.8 CM2350 F128C
• ISF3.8 CM2220 AN
• QSF3.8 CM2350 F107

The Flexplate 5521188 is also compatible with other Cummins engines such as the 4B3.9, 6B5.9, and B5.9 series. It ensures that these engines can be properly connected to their respective transmissions, providing a reliable and efficient power transfer system.

This flexplate is engineered to meet the specific requirements of Cummins engines, ensuring durability and performance. It is essential to use the correct flexplate for each engine type to maintain optimal performance and prevent potential issues ⁷.

Conclusion

The Cummins 5521188 Flexplate is a critical component in the operation of heavy-duty trucks with automatic transmissions. Its design and features contribute to efficient power transmission, smooth operation, and overall reliability of the vehicle. Regular maintenance and proper installation are key to ensuring the longevity and performance of this part. Understanding its role and compatibility with various Cummins engines is essential for effective maintenance and troubleshooting.