BMW F20 F21 F30 F31 F32 F34 Rear Differential Diff 3,15 Ratio 7603748 WARRANTY

Listing details

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

BMW F20 F21 F30 F31 F32 F34 Rear Differential Diff 3,15 Ratio is an original BMW drivetrain component designed for rear axle installation. The stable 3.15 gear ratio ensures predictable drivetrain behavior, resulting in confident handling and consistent acceleration characteristics.

Specifications and technical data

• SKU: 7603748
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7603748
• Substitutable numbers: 33107603748, 7603748, 33107603749, 7603749
• Location on the vehicle: Rear
• Category: Additional Differential Parts

Technical specifications and 3.15 gear ratio

The presented rear differential has been designed for precise torque transmission to the rear wheels. The 3.15 gear ratio is a balance between dynamics and fuel economy – it allows for reasonable engine RPM at highway speeds while maintaining good throttle response in daily use.

The placement on the vehicle at the rear axle promotes even load distribution within the drivetrain. The differential design is adapted to the suspension and drivetrain architecture of F-series models, which facilitates installation and limits the need for additional modifications.

Application in BMW F-series models

The rear differential with a 3.15 ratio is intended for BMW F-family vehicles, such as the F20, F21, F30, F31, F32, and F34. This makes it a cohesive drivetrain element across a wide range of body styles – from compact hatchbacks, through sedans and estates, to coupe and Gran Turismo versions.

Its original BMW origin ensures the maintenance of factory operating parameters, compatibility with vehicle electronics, and proper fitment with half-shafts and mounts. This is particularly important during repairs, where the repeatability of geometry settings and the absence of unwanted play in the system are crucial.

Condition, origin, and benefits of choosing a used part

The offered differential is in used condition, which allows for a significant reduction in repair costs compared to purchasing a new component, while maintaining the manufacturer's original specifications. For many BMW users, this is a reasonable compromise between price and quality, especially for mechanical components with durable construction.

If you are considering whether it is better to opt for refurbishment or a proven dismantled part, it is worth checking out our guide: Refurbished or original used – which part to choose for repairs?. The article helps you make an informed decision in the context of components such as differentials or power units.

Why choose an original BMW differential with a 3.15 ratio

Choosing an original BMW rear differential with a 3.15 ratio primarily offers:

• Factory compatibility with the drivetrain and suspension of F-series models.
• Predictable drivetrain performance thanks to the maintenance of the correct gear ratio.
• Repair cost savings by using a used part instead of a new one.
• The ability to restore factory driving parameters after a failure or wear of the previous differential.

For those planning broader modifications or retrofitting the car based on dismantled parts, the following material on retrofitting may also be useful: Retrofitting in VAG and BMW group cars: how to affordably upgrade your car using used parts. It allows for better planning of modernization work within the drivetrain and equipment.

Complementing the BMW drivetrain

If you are planning a comprehensive repair or modernization of the drivetrain area in your BMW and need other elements from the same group, such as additional differentials, housings, or mounts, check out the available parts in the Other BMW differential parts category.