Window Guide Mercedes ML W166 Front Left N/S Door Seal Guide Rail A1667250125

The Mercedes ML W166 Left Front Window Guide is an original body part from the Window Seals and Trim group, designed for guiding and stabilizing the window in the front left door. It ensures precise window movement within the guide, reduces vibrations, and supports proper door sealing, contributing to acoustic comfort and the longevity of the window regulator mechanism.

Specifications and technical data

• SKU: A1667250125
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1667250125
• Substitutable numbers: A1667250125, A 166 725 01 25
• Location on the vehicle: Front, Left
• Category: Window Seals, Gaskets & Trims

Vehicle Application and Function

The described guide is intended for installation in the front left door of the vehicle, in the area where the window is mounted and guided. Its functions include:

• stabilizing the window during raising and lowering,
• reducing lateral play and unwanted vibrations,
• working with the door seal to improve airtightness,
• protecting the window edges from excessive mechanical wear.

Thanks to its proper profile and fit to the door construction, this component supports quiet operation of the window regulator and helps maintain adequate pressure of the window against the seals.

Original Mercedes Fitment

The window guide has been designed as an original Mercedes component, meaning it offers full compatibility with the factory geometry of doors and windows in the ML W166 model. The element's design is tailored to:

• the shape of the door frame on the driver's or front passenger's side (left side of the vehicle),
• factory mounting points within the door structure,
• the original window regulator mechanism and surrounding seals.

This precise fit facilitates installation, minimizes the risk of incorrect window alignment, and preserves the system's original operating parameters.

Characteristics of a Used Part

The item is offered in a used condition, meaning it has been removed from a dismantled vehicle and was previously in operation. This type of part is a good choice when you prioritize:

• maintaining original quality and construction at a lower purchase cost,
• compatibility with factory body solutions,
• reducing the risk of fitment issues common with universal aftermarket replacements.

For window guides and seals, a used OEM part often provides a better fit than new aftermarket alternatives with simplified designs.

Benefits of Using an Original Window Guide

Installing this guide in the front left door of an ML W166 restores proper window operation and reduces common issues such as wind noise, creaking during closing, or uneven window movement. Key benefits include:

• Factory Fitment – designed for a specific vehicle model, requiring no modifications.
• Stable Window Operation – correct vertical guidance, reduced load on the window regulator.
• Door Seal Support – improved cooperation with seals, helping to minimize air leaks and moisture ingress.

This solution is particularly useful for repairs after a collision, window replacement, or refurbishment of the window regulator in the front left door.

If you are planning a comprehensive repair or upgrade of the window and door area in your Mercedes and need other parts from the same group, such as guides, surrounding seals, or trim strips, check the available parts in the Mercedes Window Seals and Trim category.

Additional Information and Selection Support

When selecting used body parts for a Mercedes, it's important to consider vehicle generation, mounting side, and door type. For this guide, it is crucial that it is intended for the front left door of the correct ML W166 body version, ensuring proper window alignment relative to the frame and seals.

If you want to better understand when it's worthwhile to opt for original dismantled parts and how to safely select them for your car, read the article Used Mercedes Parts – Original Dismantled Components, which discusses the practical aspects of using used parts in this brand's vehicles.