BMW E87 E90 E91 116i 118i 318i 320i Differential Diff 3,91 Ratio WARRANTY

Listing details

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

BMW E87 E90 120i 320i N43 Differential Rear Axle 3.91 is a rear differential from the Differentials - Diffs category, designed for installation on the rear axle of selected BMW models with the N43 engine. This is a solution for users looking for a proven drive axle with a specific gear ratio, ensuring stable power transfer and predictable vehicle behavior.

Specifications and technical data

• SKU: 7524325
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7524325
• Substitutable numbers: 33107524325, 7524325, 33107524326, 7524326
• Location on the vehicle: Rear
• Category: Differentials

Differential Purpose and Characteristics

The presented BMW rear differential is a component of the drivetrain mounted on the vehicle's rear axle. The axle housing has been designed to work with the N43 engine in Series 1 (E87) and Series 3 (E90) models, maintaining the factory acceleration and engine RPM characteristics at a given speed.

The differential gear ratio is selected to ensure:

• factory-consistent acceleration across the entire RPM range,
• stable torque transfer to the rear wheels,
• predictable vehicle behavior during acceleration and engine braking.

Construction and Rear Axle Installation

The rear axle is structurally adapted for installation in the factory mounting points on the rear axle of BMW E87 and E90. Its placement as Rear / tył means the differential works with the rear driveshafts and factory suspension, without requiring modifications to the body geometry.

Key installation features:

• dedicated mounts to the rear subframe,
• maintaining drivetrain alignment with the driveshaft and half-shafts,
• compatibility with the factory drivetrain in the models for which the differential is intended.

Benefits of Using a Used BMW Differential

Choosing a used differential from a dismantled vehicle is a solution that restores the drivetrain's functionality while maintaining factory specifications. Compared to aftermarket replacements, a BMW axle offers:

• original drivetrain operating characteristics,
• retention of the correct gear ratio matched to the N43 engine,
• compatibility with the vehicle's factory systems, such as traction control or stability control.

This solution is particularly beneficial for repairs where maintaining the car's stock driving parameters is crucial, without experimenting with different gear ratios.

Application in BMW E87 120i and E90 320i

The differential is designed to work with the N43 engine in popular BMW Series 1 and 3 models. This provides the user with a rear axle that:

• maintains the factory driving feel known from the 120i and 320i versions,
• ensures adequate dynamics for daily use,
• reduces the risk of incompatibility resulting from using an incorrect gear ratio.

This is especially important when replacing a damaged differential, where preserving the car's original character without additional modifications is desired.

Gear Ratio Selection and Technical Knowledge

When replacing a drive axle, it is crucial to match the gear ratio to the gearbox, engine power, and driving style. If you want to better understand how the rear differential's gear ratio affects vehicle behavior, consider reading our guide: Used Drive Axles and Differentials – How to Choose Gear Ratios for Your Driving Style. The article practically explains the relationships between gear ratio, dynamics, and driving comfort.

Other Differentials - BMW Diffs

If you are also looking for other gear ratio configurations or axles for different models of this brand, check out the BMW Differentials - Diffs available in our store. This will allow you to easily compare different variants and select the component best suited for your specific project or repair.