BMW Z4 Series E85 2.0i N46 Rear Differential Diff 3,38 Ratio 7550505 WARRANTY

Listing details

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

BMW Z4 Series E85 2.0i N46 Rear Differential Diff 3,38 Ratio is an original rear drivetrain assembly designed for the driven axle of the BMW Z4 E85 model with the N46 engine. The fixed 3,38 gear ratio ensures predictable drivetrain behavior, stable acceleration, and consistent operating characteristics with the factory gearbox and vehicle electronics.

Specifications and technical data

• SKU: 7550506
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7550505
• Substitutable numbers: 33107550505, 7550505, 33107550506, 7550506
• Location on the vehicle: Rear
• Category: Additional Differential Parts

Purpose and function in the drivetrain

The presented differential is a component of the rear drive axle, responsible for distributing torque to the rear wheels and ensuring proper cooperation with the driveshaft and half-shafts. The applied 3,38 ratio is tailored to the characteristics of the N46 unit in the BMW Z4 E85, which allows for maintaining factory driving parameters, predictable engine RPM at highway speeds, and appropriate dynamics during acceleration.

Its location at the rear of the vehicle facilitates integration with the existing suspension and drivetrain without the need for interference with the vehicle's structural design.

Benefits of using an original BMW differential

Using an original differential with the correct gear ratio results in:

• maintaining factory acceleration characteristics and engine RPM,
• proper cooperation with traction and stability control systems,
• consistent operation with the stock gearbox and control electronics,
• appropriate loads for half-shafts and wheel bearings.

For the user, this means stable handling, predictable throttle response, and the absence of unwanted vibrations resulting from an incorrectly selected gear ratio. Choosing an original BMW component reduces the risk of compatibility issues and premature wear of mating parts.

Condition, verification, and selection by part numbers

The differential comes from disassembly and is offered as a used original part, which in practice allows combining an attractive price with the preservation of factory technical specifications. Before installation, a standard check of seals, backlash, and oil condition is recommended, in accordance with BMW service procedures.

To precisely confirm compatibility with a specific version of the BMW Z4 E85, it is worth using the OEM part number and interchangeable numbers assigned to this differential. This helps avoid mistakes when selecting the gear ratio and axle design version, especially in the case of cars after modifications or with individual drivetrain configurations.

Practical tips on checking component compatibility by numbers can be found in our guide: Buying parts online without risk – 5 ways to verify OEM numbers and select a BMW differential.

Installation and practical application

The differential is designed for installation in the rear of the vehicle, in place of the factory drive axle. Thanks to the preservation of the original design, it is possible to use the stock mounting points, which simplifies workshop work and shortens replacement time. In most cases, installation comes down to:

• removing the old axle along with disconnecting the driveshaft and half-shafts,
• installing the offered differential in the factory mounting points,
• connecting the driveshaft and half-shafts,
• refilling oil in accordance with the manufacturer's recommendations.

This approach allows for restoring the proper operation of the drivetrain without the need for structural modifications, which is particularly important in sports-recreational cars such as the BMW Z4 E85.

Expanding BMW drivetrain repairs

If you are planning a comprehensive repair or upgrade of the drivetrain area in your BMW and need other elements from the same group, such as additional axles, gears, or components cooperating with the differential, check the available parts in the Other BMW differential parts category.