Audi S4 B9 S5 F5 SQ5 FY 3.0 Rear Axle Differential 43:13 QQS 0D3500043 WARRANTY

Listing details

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

Audi S4 B9 S5 F5 SQ5 FY 3.0 Rear Axle Differential 43:13 QQS is an original drivetrain component from the Differentials category, designed for installation on the rear axle in selected, high-performance versions of Audi models. This used rear axle differential with the correct gear ratio provides a solid foundation for professional repairs or drivetrain modifications in vehicles equipped with a 3.0 engine, ensuring consistent drivetrain operation and stable vehicle handling.

Specifications and technical data

• SKU: 0D3500043
• Mark: Audi
• Condition: Used
• OEM Part Number: 0D3500043
• Substitutable numbers: 0D3500043, 0D3 500 043
• Location on the vehicle: Rear
• Part type: Differential & Housing Assembly
• Category: Differentials

Purpose and function of the rear differential

The presented rear axle differential is a component of the rear axle differential system, responsible for distributing torque between the wheels and working in conjunction with the all-wheel-drive system in Audi sports models. The 43:13 gear ratio used is characteristic of the 3.0 configuration in the Audi S4 B9, S5 F5, and SQ5 FY, which allows for maintaining factory acceleration characteristics, engine RPM, and driving comfort.

Its location at the rear axle means the differential works in direct connection with the driveshaft and half-shafts, and its correct selection is crucial for the durability of the entire drivetrain and proper cooperation with the vehicle's electronics.

Benefits of using an original Audi differential

Using an original salvaged differential in Audi models with a 3.0 engine allows for maintaining factory drivetrain performance parameters without the need to interfere with controller software or change other components. This solution is particularly beneficial for:

• repairing an existing rear axle after mechanical damage,
• restoring the factory configuration after modifications,
• building a project based on stock gear ratios.

This used component from the Differentials group allows for cost reduction compared to a new part, while maintaining structural and assembly compatibility with the factory Audi solution.

Assembly aspects and vehicle fitment

The rear differential is intended for installation in the rear of the vehicle, replacing the factory axle. When selecting, it is important to pay attention to the compatibility of the gear ratio, body type, and drivetrain version to avoid discrepancies in drivetrain operation and errors in electronic systems. A properly selected rear axle facilitates installation in standard mounting points and ensures compatibility with existing half-shafts and the driveshaft.

Due to the nature of the component, installation in a specialized workshop is recommended to verify seals, backlash, and the correct alignment of the differential relative to other components. This approach minimizes the risk of noise, vibrations, and premature tire wear.

Gear ratio selection and technical knowledge

When replacing the rear axle, it is crucial to match the gear ratio to the existing drivetrain configuration and the driver's driving style. An incorrect selection can result in improper operation of assistance systems, changes in acceleration characteristics, and increased fuel consumption. To better understand the relationship between differential gear ratios, transmission operation, and driving comfort, it is worth checking out our guide Salvaged drive axles and differentials – how to choose gear ratios for your driving style, which discusses definitions, configuration examples, and practical tips regarding used components.

For users interested in a broader context of how all-wheel-drive systems work in the VAG group, an article comparing different AWD systems may also be helpful, available at the link xDrive, 4Matic, quattro or 4Motion – a comparison of AWD systems from BMW, Mercedes, Audi, and VW, where the role of differentials in torque distribution is described, among other things.

Expanding the Audi drivetrain

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, or related parts, check out the available parts in the Audi Differentials category.