Mercedes W177 W247 Wiper Arm Rear Window Glass Cover A2478206400

Mercedes W177 W247 Wiper Arm Rear Window Glass Cover is an original component from the Wiper arms group, designed for operation on the rear window. It ensures stable wiper blade guidance, even water removal, and improved visibility in difficult weather conditions, which directly impacts driving safety.

Specifications and technical data

• SKU: A2478206400-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2478206400
• Substitutable numbers: A2478206400, A 247 820 64 00
• Location on the vehicle: Rear
• Category: Wiper Arms

Purpose and function of the wiper arm

The rear wiper arm in Mercedes W177 and W247 series models is responsible for precisely pressing the blade against the glass and stably guiding its movement along the working arc. Its placement in the rear window zone means this component operates under exposure to dirt, road salt, and fluctuating temperatures, which is why its proper condition is crucial for clear visibility in the rearview mirror.

A properly selected arm minimizes vibrations, reduces noise during wiper operation, and decreases the risk of uneven blade wear. Correct fitment to the specific body generation allows for maintaining the factory wiper geometry and avoiding blind spots on the glass.

Construction and body fitment

The rear wiper arm in this Mercedes model is designed to work with the drive mechanism and the wiper shaft in the rear part of the body. The design provides the appropriate mounting angle and range of motion, which translates into:

• proper blade pressure against the glass surface,
• even removal of water and dirt,
• reduction of blade skipping or "chattering" on the glass.

The original origin from the Mercedes brand means maintaining factory dimensional tolerances, thanks to which the arm works with the existing mechanism without the need for modifications. This is particularly important in the case of modern bodies, where mounting space is limited and the geometry of the rear window requires precise wiper guidance.

Characteristics of the used component

The presented wiper arm comes from the group of parts in used condition, which in practice means that the element was previously in service but retains the functionality required for further operation. For many users, this is a reasonable compromise between cost and maintaining the original build quality characteristic of Mercedes.

Choosing a used rear wiper arm is particularly justified in situations where the existing component has suffered mechanical damage (e.g., breakage during snow removal) or corrosion in the mounting area. Using an original component from the secondary market allows for restoring the proper operation of the wiper system without the need to invest in a new replacement of unknown origin.

Vehicle placement and mounting aspects

The arm is intended for installation in the rear of the vehicle area, on the rear wiper shaft. Proper seating on the splines or cone (depending on the specific version of the mechanism) is crucial for maintaining the correct operating angle and avoiding collisions with the edges of the glass or the spoiler.

During installation, it is worth paying attention to:

• the resting position of the wiper relative to the lower edge of the glass,
• the tightening torque of the mounting nut to avoid looseness or thread damage,
• the condition of the mounting socket and the seal around the wiper shaft.

Due to the factory fitment to the Mercedes W177 and W247 series body, the arm works with the original blade and drive mechanism, which facilitates service and subsequent replacement of the blade itself.

Benefits of using an original wiper arm

Using an original rear wiper arm in a Mercedes brings a number of practical benefits:

• Stable wiper operation – reduction of vibrations and noise, especially at higher speeds.
• Better rear visibility – even removal of water and mud from the entire designed working surface.
• Full body compatibility – maintaining the factory range of motion and resting position.
• Visual consistency – appearance consistent with the Mercedes styling line, without accidental differences in shape or color.

For users who value functionality and aesthetics, choosing an original arm from the Wiper arms category is a solution that allows maintaining the vehicle at a standard close to factory condition.

If you are planning a comprehensive repair or upgrade of the rear window area in your Mercedes and need other elements from the same group, such as additional arms, mounts, or components working with the wiper mechanism, check the available parts in the Mercedes Wiper arms category.