Audi R8 Rear Upper Control Arm Left N/S 4.2 TSI 420505361

Audi R8 Rear Upper Control Arm Left N/S is a precision component from the Control arms and ball joints group, designed for operation on the rear axle on the left side. It is responsible for stable wheel guidance, maintaining correct suspension geometry, and predictable vehicle behavior during acceleration, braking, and cornering.

Specifications and technical data

• SKU: 420505361
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 420505361
• Substitutable numbers: 420505361, 420 505 361
• Location on the vehicle: Rear, Left
• Part type: Control Arm & Ball Joint Assembly
• Category: Control Arms, Ball Joints & Assemblies

Purpose and function in the suspension

The Audi R8 Rear Upper Control Arm Left N/S operates in the rear axle area, on the driver's side. Its task is to maintain the correct position of the wheel hub relative to the body, control camber and toe angles, and dampen forces acting on the suspension during dynamic driving. This ensures that the chassis maintains stability and tires wear evenly.

This component works in conjunction with other control arms and ball joints to form a cohesive wheel guidance system. In the event of play, worn bushings, or structural damage, replacing the upper control arm is crucial for restoring correct geometry and reliable vehicle handling.

Benefits of using the original design

The control arm has been designed as a part meeting the factory specifications of the Audi R8, which translates into:

• precise fitment to the mounting points on the body and steering knuckle,
• proper cooperation with stock ball joints and other suspension components,
• preservation of the handling characteristics intended by the vehicle manufacturer.

As a result, installation is predictable, and after setting the suspension geometry, the car regains its directional stability, steering precision, and repeatable behavior at high speeds.

Component condition and service application

The offered control arm is in used condition, making it an attractive solution for repairs where cost-effectiveness is a priority. It is a good solution in situations where a quick replacement of a damaged component is necessary, and the priority is to restore proper suspension operation within a controlled budget.

Due to its location in the rear of the vehicle on the left side, this component is particularly important in cases of damage resulting from curb impacts, road irregularities, or collisions affecting rear axle geometry. Replacing the upper control arm helps reduce excessive tire wear, improve braking stability, and minimize unwanted vehicle pulling.

Importance for safety and driving comfort

A functional Audi R8 Rear Upper Control Arm Left N/S has a direct impact on:

• maintaining constant tire contact with the road surface,
• vehicle stability in corners and during lane changes,
• reduction of vibrations and noise transmitted from the suspension to the body,
• proper cooperation with safety systems such as ABS or traction control.

For Audi R8 4.2 TSI owners who expect predictable car behavior and repeatable handling parameters, replacing a worn control arm with a functional unit is one of the essential service steps in the suspension area.

Control arms and ball joints – additional materials and related products

To better understand the role of these types of components in the entire chassis system, it is worth checking out the guide material describing the construction and operation of the suspension – practical information can be found in the article Suspension system – a comprehensive guide to shock absorbers, control arms, and stabilizers. This is a helpful source of knowledge when planning broader suspension service work.

If you are planning a comprehensive repair or upgrade of the suspension zone in your BMW and need other components from the same group, such as additional control arms, ball joints, or mounting hardware, check the available parts in the BMW Control arms and ball joints category.

For additional tips on planning repairs and optimizing vehicle operating costs, you can look for the practical list of the most frequently serviced components described in the article TOP 10 most frequently replaced parts in your car.