Mercedes W166 Door Inside Sealing Seal Gasket Front Left N/S Window A1667250365

Mercedes W166 Front Left Door Window Seal Front Left is an original body part from the Door Seals group, designed for installation in the front left door of Mercedes vehicles. The precisely fitted sealing profile helps reduce noise, improve window seal, and maintain stable window guidance in the track.

Specifications and technical data

• SKU: A1667250365
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1667250365
• Substitutable numbers: A1667250365, A 166 725 03 65, A2927250300, A 292 725 03 00
• Location on the vehicle: Front, Left
• Category: Door Seals

Vehicle Application and Placement

The presented seal is designed for installation in the front left door area, where the window meets the door frame. Its placement on the vehicle, designated as front – left side, means the part works with the window lifting mechanism and the driver's door structure in vehicles with a classic left-hand drive configuration.

This precise fit ensures correct window geometry, reduces vibrations, and limits the ingress of water and contaminants into the door and cabin.

Technical Function of the Door Window Seal

The front door window seal performs several key operational functions:

• Creates a flexible barrier between the window and the door frame,
• Supports proper window guidance during opening and closing,
• Limits the penetration of water, dust, and air into the door interior,
• Contributes to cabin acoustic comfort by reducing wind noise.

Thanks to its proper profile and fit with the Mercedes door construction, the seal helps maintain stable operation of the window lifting mechanism and reduces the risk of jamming or excessive play.

Benefits of Using an Original Mercedes Seal

Using an original seal dedicated to a specific mounting position in the body brings tangible technical benefits:

• Precise fit with the door frame – no need for adjustments or cutting the part,
• Maintains the factory-set contact line between the window and the seal,
• Reduces the risk of leaks in the upper and side window areas,
• More stable window operation in the track with frequent opening and closing.

Parts from this group are particularly important in vehicles operated in varying weather conditions, where seal integrity and proper window guidance contribute to the durability of door mechanisms and user comfort.

Product Characteristics and Fitment

The seal is intended for Mercedes vehicles with a door construction consistent with the W166 series. The product is a used part, meaning it is a pre-owned item that retains functionality suitable for further use after proper installation.

For correct part selection, pay attention to:

• Body compatibility with the W166 series,
• Placement on the vehicle designated as front – left side,
• Belonging to the Door Seals group, which facilitates integration with other door components.

Identification Information and Service Application

The part has an assigned OEM part number and relevant interchangeable numbers, which facilitate compatibility verification in service catalogs and parts selection systems. This allows for precise confirmation of the seal's compatibility with a specific body version and vehicle year.

In the service process, this type of seal is most commonly replaced in cases of:

• Wear of the flexible material and loss of seal integrity,
• Mechanical damage resulting from interference with the door or windows,
• Problems with smooth window operation in the track.

Expanding the Scope of Service Work

If you are planning a comprehensive repair or upgrade of the door area in your Mercedes and require other parts from the same group, such as perimeter seals, frame seals, or additional soundproofing profiles, check the available parts in the Mercedes Door Seals category.

For those interested in broader use of used parts in vehicle modernization projects, practical tips on component selection and cost optimization can be found in the article Emotion and Design – Visual and Mechanical Tuning of a Seat Using Used Components.