Audi A7 4G 3.0 TDI Quattro Rear Differential Diff 37:9 MNB 0BC500044A WARRANTY

Listing details

The differential is sold with a 90-day warranty! It was tested before removal and is in full working order.

Audi A7 4G 3.0 TDI Quattro Rear Differential Diff 37:9 MNB is a factory-original drivetrain component from the Differentials group, designed for installation on the rear axle of the Quattro all-wheel-drive system. This solution is engineered for stable torque transfer, precise gear operation, and maintaining the correct gear ratio characteristics in a dynamic premium-class sedan.

Specifications and technical data

• SKU: 0BC500044A
• Mark: Audi
• Condition: Used
• OEM Part Number: 0BC500044A
• Substitutable numbers: 0BC500044A, 0BC 500 044 A
• Location on the vehicle: Rear
• Category: Differentials

Purpose and function in the drivetrain

The described rear differential is dedicated to the Quattro drivetrain in the Audi A7 4G generation model with a 3.0 TDI engine. As a component mounted on the rear axle, it is responsible for distributing torque between the wheels, working in conjunction with the driveshaft, and maintaining the correct final drive ratio, which directly impacts acceleration, engine RPM at a given speed, and the overall refinement of the drivetrain.

The 37:9 MNB gear ratio configuration ensures consistency with the manufacturer's original specifications regarding dynamics, fuel consumption, and transmission operation. Consequently, replacing a worn or damaged differential with this model allows for the preservation of the vehicle's original driving characteristics without the need for ECU software intervention or modifications to other drivetrain components.

Construction and technical characteristics

The rear differential in the Audi A7 4G 3.0 TDI Quattro is a gear assembly enclosed in a rigid housing, adapted to handle the high torque of the diesel engine. The axle construction is optimized for all-wheel-drive operation, which means properly selected final drive ratios, gear geometry, and mounting points for the suspension and chassis.

In practice, this means:

• stable load transfer during highway driving and dynamic acceleration,
• maintaining proper cooperation with traction control and electronic stability systems,
• reduction of noise and vibration thanks to factory gear geometry.

By using an original design, the differential maintains compatibility with factory mounting points, half-shafts, and the driveshaft, which facilitates installation and minimizes the risk of fitment issues.

Condition, origin, and service application

The presented item is a used part sourced from vehicle dismantling, allowing for an economical repair of the drivetrain while maintaining factory specifications. This type of differential is particularly useful in situations where the vehicle exhibits symptoms such as whining from the rear drivetrain, uneven torque transfer, mechanical housing damage, or the effects of high-mileage wear.

Replacing the rear axle with a model matching the factory gear ratio is crucial for maintaining proper cooperation with the existing transmission and control units. Using the correct differential helps avoid issues with electronic system errors, incorrect speed readings, or excessive load on other drivetrain components.

Gear ratio selection and technical support

When selecting a rear differential for the Audi A7 4G 3.0 TDI Quattro, it is extremely important to match the gear ratio to the specific drivetrain configuration and driving style. The right choice affects perceived dynamics, driving comfort, and component durability. To better understand the relationships between gear ratios, engine performance, and transmission characteristics, it is worth checking our guide: Dismantled drive axles and differentials – how to choose gear ratios for your driving style.

Complementary Audi Differentials

If you are planning a comprehensive repair or upgrade of the drivetrain area in your Audi and need other components from the same group, such as additional axles, differentials with different ratios, or compatible gear assemblies, check out the available parts in the Audi Differentials category.