Mercedes W639 Rear Window Tailgate Trunk Wiper Arm A6398201444

Visual condition of the part

The product shows signs of use visible in the photos.

Mercedes W639 Rear Window Tailgate Trunk Wiper Arm is an original component designed for rear window operation, ensuring stable blade guidance and effective water removal. Thanks to its factory geometry and precise fit for the W639 model, the wiping mechanism remains accurate and predictable, which improves visibility and driving comfort in the rain. This is a solution for users who are looking for a part consistent with the manufacturer's design while maintaining the technical integrity of the vehicle.

Specifications and technical data

• SKU: A6398201444
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6398201444
• Substitutable numbers: A6398201444, A 639 820 14 44
• Location on the vehicle: Rear
• Category: Wiper Arms

Purpose and function in the vehicle

The rear tailgate wiper arm has been designed specifically for installation on the rear window of the Mercedes W639. It is responsible for the stable mounting of the blade, proper pressure against the glass, and uniform movement along the working arc, which is crucial for maintaining clear visibility in the rearview mirror during precipitation and road debris.

Its placement on the rear of the body means the component operates in demanding conditions – it is exposed to water, salt, dust, and temperature fluctuations. The arm's construction is adapted to these loads to ensure repeatable, smooth movement and to limit blade vibration even during long-term use.

Construction and fitment for Mercedes W639

The wiper arm in question belongs to the Wiper arms category and is factory-adapted to the geometry of the Mercedes W639 tailgate. The properly selected length, operating angle, and mounting method allow for:

• secure seating on the wiper mechanism shaft,
• proper guidance of the blade across the glass surface,
• maintenance of the cleaning area intended by the manufacturer.

As a result, there is no need to modify the mounting or interfere with the tailgate structure – the arm works with the original drive mechanism, which facilitates installation and service.

Performance characteristics and benefits

As an original Mercedes component, the rear wiper arm ensures consistency with other parts of the wiping system. The most important benefits include:

• stable blade pressure against the glass, which translates into uniform removal of water and impurities,
• maintenance of the correct operating path, minimizing blind spots on the rear window,
• compatibility with standard blades intended for this model,
• preservation of the factory appearance of the rear bodywork.

The used condition means that the component comes from disassembly, which for many users is a reasonable compromise between cost and maintaining the original technical specifications of the vehicle.

Installation and service application

The rear wiper arm in the Mercedes W639 is a typical service item, replaced in the event of joint wear, mechanical damage, or issues with blade pressure. In practice, installation involves:

• removing the old arm from the mechanism shaft,
• cleaning the mounting socket,
• seating and tightening the new arm according to the service position.

With proper installation, the rear window wiping system regains full functionality, and the driver gains better control over the situation behind the vehicle in difficult weather conditions.

If you are planning a comprehensive repair or upgrade of the rear window visibility zone in your Mercedes and need other elements from the same group, such as additional arms, mounts, or compatible blade holders, check the available parts in the Mercedes Wiper arms category.

Substantive support and vehicle development

For drivers who, alongside maintaining the efficiency of the wiping system, are thinking about improving the car's performance, a practical guide on drive system modifications may be useful. In the context of conscious service and tuning, it is worth reading the material: How to increase engine power: a practical guide to engine tuning with used parts, which helps in better planning work on the car and combining daily operation with reasonable upgrades.