BMW 3 Series E91 K4 Rear Left Right N/O/S Sport Coil Spring Suspension Set

BMW 3 Series E91 K4 Rear Left Right N/O/S Sport Coil Spring Suspension Set is a set of rear sport suspension springs designed for the left and right axle of the BMW 3 Series E91 model. The set belongs to the Leaf and coil springs group, providing precise support for the rear of the body and stable vehicle handling. This is a solution for drivers expecting more dynamic suspension characteristics while maintaining the factory geometry of the chassis.

Specifications and technical data

• SKU: E91 K4 Rear Coil Spring Set
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: E91 K4
• Substitutable numbers: E91 K4, AS
• Location on the vehicle: Rear, Right, Left
• Category: Leaf & Coil Springs

Purpose and function in the BMW E91 suspension

The presented set of rear sport suspension springs is designed to work on both sides of the axle – right and left. It is responsible for maintaining the correct height of the rear body, transferring dynamic loads, and working with shock absorbers to dampen road irregularities. Thanks to their sport characteristics, the springs improve the car's response to changes in load and direction, which translates into more precise cornering.

The placement on the vehicle covers the rear axle, making the set a key element for stability during acceleration, braking, and driving with a load in the trunk. Properly selected spring stiffness supports the rear suspension in typical road conditions as well as during a more dynamic driving style.

Performance characteristics and advantages of the set

The set of sport springs for the BMW 3 Series E91 ensures consistent operation on both sides of the axle, which minimizes the risk of suspension asymmetry. Using a single, matched set of springs instead of individual components makes it easier to maintain an even body height and predictable vehicle behavior.

Key benefits include:

• increased rear axle stability during high-speed cornering,
• more direct suspension response to load changes,
• consistent operation of the left and right sides due to the use of a complete set,
• preservation of the sport character typical of the BMW brand.

The product comes from the Leaf and coil springs group, which means it has been designed to withstand significant operational loads and work with factory rear axle suspension components.

Component condition and installation aspects

The spring set is offered as a used item, which allows for an economical replacement of worn or damaged suspension components while maintaining the original performance characteristics. A used set of springs is particularly attractive for post-accident repairs or restoring the factory driving properties of the vehicle when compliance with manufacturer-applied solutions is a priority.

Due to its dedicated design for the rear axle of the BMW 3 Series E91, installation takes place at the standard mounting points provided by the vehicle manufacturer. In practice, this means it can be integrated with existing shock absorbers and other suspension elements without the need for structural modifications.

Selection and compatibility within the Leaf and coil springs group

When selecting suspension springs for the BMW 3 Series E91, it is crucial to match them to the specific body version and rear axle configuration. Using a complete set of rear sport springs allows for maintaining consistent suspension performance and reducing the risk of uneven tire wear or incorrect geometry.

If you are planning a comprehensive repair or upgrade of the rear suspension area in your BMW and need other elements from the same group, such as additional springs, leaf springs, or mounting brackets, check the available parts in the BMW Leaf and coil springs category.

Technical support and knowledge about vehicle systems

When working with suspension components and other key vehicle systems, it is worth using reliable sources of technical knowledge. For a better understanding of the impact of individual components on engine durability and operational safety, you can refer to an article describing the relationship between engine operating temperature and its service life: Engine cooling system – overheating, repair, and used radiators. This will allow you to view the suspension upgrade in the broader context of the car's overall technical condition.