3936138
Accessory Drive Gear
Cummins®

Introduction

The Cummins 3936138 Accessory Drive Gear is a critical component for commercial trucks, facilitating the transfer of power from the engine to various accessories. This ensures that essential systems, such as the alternator, power steering, and air conditioning compressor, receive the necessary power to function correctly.

Basic Concepts of Accessory Drive Gear

An Accessory Drive Gear is a mechanical component that transmits power from the engine to auxiliary systems within a truck. It operates by engaging with a series of belts or chains that connect to different accessories. The gear’s rotation, driven by the engine’s crankshaft, powers these accessories, allowing them to perform their designated functions. This system ensures that all components requiring mechanical power are efficiently driven, contributing to the overall performance and functionality of the vehicle ¹.

Purpose of the Cummins 3936138 Accessory Drive Gear

The Cummins 3936138 Accessory Drive Gear is specifically designed to drive various engine accessories in commercial trucks. Its role involves transferring rotational force from the engine to accessories such as the alternator, water pump, and air conditioning compressor. By ensuring these components receive the necessary power, the gear contributes to the efficient operation of the truck’s engine and its auxiliary systems ².

Key Features

The Cummins 3936138 Accessory Drive Gear is characterized by its robust design and the use of high-quality materials. It is engineered to withstand the demanding conditions of commercial truck operations. Key features include precision machining for accurate fit and function, durable materials that resist wear and corrosion, and a design that enhances performance and longevity. These characteristics ensure the gear operates efficiently under various conditions, contributing to the reliability of the truck’s engine system ³.

Benefits

Utilizing the Cummins 3936138 Accessory Drive Gear offers several advantages. It contributes to improved engine efficiency by ensuring accessories operate smoothly and reliably. The gear’s durable construction and precise engineering lead to enhanced reliability, reducing the likelihood of unexpected failures. Additionally, its efficient design can lead to potential cost savings for fleet operators by minimizing maintenance needs and extending the lifespan of the truck’s engine accessories.

Troubleshooting and Maintenance

Common issues with the Cummins 3936138 Accessory Drive Gear may include wear and tear, misalignment, or damage to the gear teeth. Regular maintenance practices, such as inspecting for signs of wear, ensuring proper alignment, and replacing worn components, are recommended to maintain optimal performance. Troubleshooting steps may involve checking for proper belt tension, inspecting for damage, and ensuring the gear is correctly installed and aligned with other components.

Integration with Engine Systems

The Cummins 3936138 Accessory Drive Gear integrates seamlessly with other engine systems and components. It plays a role in the overall functionality of the truck by ensuring that power is efficiently distributed to essential accessories. This integration is crucial for the harmonious operation of the engine and its auxiliary systems, contributing to the truck’s performance and reliability.

Performance Under Various Conditions

The Cummins 3936138 Accessory Drive Gear is designed to perform under a range of operating conditions. It operates efficiently across varying temperatures, loads, and speeds, ensuring that engine accessories receive the necessary power to function correctly. Its robust design and high-quality materials enable it to withstand the rigors of commercial truck operations, maintaining performance and reliability under diverse conditions.

Historical Development and Technological Advancements

The development of accessory drive gears has evolved significantly over the years, with technological advancements leading to improvements in design, materials, and functionality. The Cummins 3936138 represents the culmination of these advancements, incorporating features and technologies that enhance its performance, durability, and efficiency. This evolution reflects the ongoing commitment to innovation in the automotive and heavy-duty truck industries.

Cummins: A Brief Overview

Cummins Inc. is a global power leader that designs, manufactures, and distributes engines, filtration, and power generation products. With a rich history of innovation and quality, Cummins has established itself as a trusted name in the commercial truck industry. The company’s extensive product range and commitment to excellence are evident in the design and quality of the Cummins 3936138 Accessory Drive Gear, underscoring its position as a leader in the industry.

Accessory Drive Gear 3936138 Compatibility with Cummins Engines

The Accessory Drive Gear part number 3936138, manufactured by Cummins, is designed to fit a variety of Cummins engines. This part plays a crucial role in the engine’s accessory drive system, ensuring that components such as the alternator, water pump, and air conditioning compressor operate correctly. Below is a detailed breakdown of the engines with which this accessory drive gear is compatible:

4B Series Engines

• 4B3.9
• QSB3.9 30 CM550
• QSB3.9 CM2880 B138

6B Series Engines

• 6B5.9

6C Series Engines

• 6C8.3
• QSC8.3 CM554
• QSC8.3 CM850(CM2850)

B Series Engines

• B4.5
• B5.9 CM2670 B166C
• B5.9 G
• B5.9 GAS PLUS CM556

C Series Engines

• C GAS PLUS CM556
• C8.3 G

ISB Series Engines

• ISB CM550

ISC Series Engines

• ISC CM554

ISL Series Engines

• ISL CM554

QSB Series Engines

• QSB5.9 30 CM550
• QSB5.9 44 CM550
• QSB5.9 CM2880 B139

QSC Series Engines

• QSC9 CM2250/QSL9 CM2250

QSL Series Engines

• QSL8.9 CM2150 L141
• QSL9 CM2250
• QSL9 CM2350 L102
• QSL9 CM554
• QSL9 CM850(CM2850)

This accessory drive gear is engineered to provide reliable performance across a wide range of Cummins engines, ensuring that the engine’s accessories are driven efficiently and effectively.

Role of Part 3936138 Accessory Drive Gear in Engine Systems

The Accessory Drive Gear, identified by part number 3936138, is integral to the efficient operation of various engine components. It is responsible for transferring rotational force from the engine’s crankshaft to multiple accessories, ensuring they function in harmony with the engine’s operation.

Interaction with the Drive System

The Accessory Drive Gear is a key component in the drive system. It engages with the crankshaft pulley, converting the engine’s rotational energy into mechanical power. This power is then distributed to various engine accessories, enabling them to perform their designated functions effectively.

Front Gear Train Accessory

In the front gear train accessory setup, the Accessory Drive Gear plays a significant role. It meshes with other gears in the front gear train, facilitating the transfer of power to accessories located at the front of the engine. This setup ensures that accessories such as the alternator, power steering pump, and air conditioning compressor receive the necessary drive to operate.

Front Gear Train Accessory Drive

When considering the front gear train accessory drive, the Accessory Drive Gear is essential for maintaining the correct gear ratio. This ratio is vital for ensuring that the accessories driven by the front gear train operate at the optimal speed, balancing efficiency and performance.

Hydraulic Pump Adapter and Kit

In systems utilizing a hydraulic pump adapter or a hydraulic pump adapter kit, the Accessory Drive Gear is responsible for driving the hydraulic pump. This ensures that the hydraulic system receives consistent and reliable power, which is essential for the operation of hydraulic components within the engine system.

Hydraulic Pump Drive

Directly driving the hydraulic pump, the Accessory Drive Gear ensures that the pump operates at the correct speed. This is important for maintaining the pressure and flow rates necessary for the hydraulic system to function correctly, supporting various engine operations and controls.

Mounting and Front Gear Train Accessory

The mounting of the Accessory Drive Gear is crucial for its stable operation within the front gear train accessory system. Proper mounting ensures that the gear remains aligned and securely in place, allowing for smooth and efficient power transmission to the front-mounted accessories.

Conclusion

In summary, the Accessory Drive Gear (part 3936138) is a fundamental component in the engine’s accessory drive system. Its role in transferring power from the crankshaft to various engine accessories ensures that these components operate efficiently and in sync with the engine’s performance.