BMW 1 3 Series E87 LCI E90 Rear Differential Diff 4,10 Ratio 7555315 WARRANTY

BMW 1 3 Series E87 LCI E90 Rear Differential Diff 4,10 Ratio with a 4.10 gear ratio is a factory-spec drivetrain component designed for rear axle installation. As a part from the Differentials category, it ensures proper torque distribution to the wheels, stable handling, and predictable vehicle behavior during acceleration and engine braking. This is a solution for users who expect compliance with factory specifications and wish to maintain the handling characteristics typical of rear-wheel-drive BMW models.

Specifications and technical data

• SKU: 7555315
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7555315
• Substitutable numbers: 33107555315, 7555315, 33107555316, 7555316
• Location on the vehicle: Rear
• Category: Differentials

Purpose and function in the drivetrain

The offered rear differential is designed to operate in the drive axle of BMW 1 and 3 Series E87 LCI / E90 generations. Positioned on the rear axle, the differential is responsible for:

• transferring torque from the driveshaft to the half-shafts,
• adjusting wheel rotation speed when cornering,
• maintaining traction stability under various road conditions.

The 4.10 gear ratio promotes dynamic acceleration, which is particularly noticeable in lower gears and during city driving. At the same time, the balance between performance and driving comfort characteristic of BMW is maintained.

Construction and performance parameters

The differential belongs to the Differentials group, which includes components responsible for precise torque management in the drivetrain. The design is based on a classic bevel gear and differential assembly, adapted to work with the rear suspension of E87 LCI and E90 models.

Key performance features of this component include:

• factory mounting geometry, facilitating installation in original body points,
• gear ratio characteristics selected for the engines and transmissions used in these generations,
• compatibility with the standard BMW rear-wheel-drive architecture.

By maintaining the original design concept, the differential allows for seamless integration with the existing drivetrain without the need for modifying associated components.

Practical application and benefits of installation

By installing this rear differential in a BMW 1 or 3 Series, the user primarily gains drivetrain consistency in line with the manufacturer's factory assumptions. This is particularly important in vehicles where:

• it is necessary to replace a worn or damaged differential,
• post-accident repair of the rear drivetrain section is being performed,
• maintaining standard acceleration and engine RPM characteristics is essential.

The properly selected 4.10 gear ratio affects perceived dynamics, which will be appreciated by drivers who prefer a more responsive throttle. At the same time, the vehicle's predictable behavior is maintained, which is important both in daily use and on longer trips.

Condition, origin, and fitment

The differential comes from a dismantled BMW vehicle, meaning it is a component compliant with the manufacturer's factory specifications. As a used part, it represents a reasonable compromise between repair costs and maintaining original build quality and fitment.

To correctly select a differential for a specific engine and transmission version, it is worth verifying the gear ratio compatibility and markings against the vehicle documentation or the numbers found on the currently installed component. This helps avoid differences in driving characteristics after replacement.

Technical support and additional materials

If you want to better understand how the final drive ratio affects vehicle behavior and how to choose a configuration for your driving style, check out our guide: Dismantled final drives and differentials – how to choose gear ratios for your driving style. You will find practical tips on interpreting gear ratios, compatibility with specific models, and the differences between used and reconditioned components.

If you are planning a comprehensive repair or upgrade of the drivetrain in your BMW and need other parts from the same group, such as final drives, main gears, or other differentials, check out the available parts in the BMW Differentials category.

For those considering performance improvements while maintaining reasonable costs, the article on tuning with used components may also be helpful: Tuning with used parts – how to gain performance without spending a fortune. It allows for better planning of drivetrain modifications using dismantled components.