Mercedes W221 Window Regulator Lifter Mechanism Rear Left Door N/S A2217300779

Mercedes W221 Window Regulator Lifter Mechanism Rear Left Door N/S is an original component from the Window regulators and motors group, designed for the rear left window in the S-Class body. It enables stable, smooth operation of the window in the door, ensuring proper guidance and reliable lifting and lowering. This solution is dedicated to users who expect compatibility with the factory installation and the preservation of the vehicle's original functionality.

Specifications and technical data

• SKU: A2217300779
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2217300779
• Substitutable numbers: A2217300779, A 221 730 07 79, KD
• Location on the vehicle: Rear, Left
• Category: Window Motors & Regulators

Purpose and function of the mechanism

The presented mechanism is designed to operate in the rear left window area, responsible for precise window guidance in the tracks and power transmission from the control system. Thanks to the correct geometry and fit to the door structure, this component works with the factory electrical system, maintaining the original operating characteristics.

The window regulator mechanism in this model is responsible for, among other things:

• stable holding of the window in the set position,
• even lifting and lowering without jerking,
• cooperation with factory window control switches,
• proper closing of the window in the rear door on the driver's side.

Benefits of using an original Mercedes component

Using an original mechanism from the Window regulators and motors group in the S-Class model allows for maintaining the factory operating parameters of the window system. The design is matched to the door, mounting points, and window travel range, which reduces the risk of stress and accelerated wear of the guides or seals.

Key advantages of this solution include:

• compatibility with the factory electrical installation and control,
• proper fit to the geometry of the rear left door,
• preservation of the original window operating quality,
• possibility of use as a replacement for a worn or damaged mechanism without interfering with the door structure.

Installation and operational characteristics

The mechanism is intended for installation in the rear left part of the body, in the place of the factory window regulator. The arrangement of mounting points and the way the cable and arms are routed are adapted to the door structure, which facilitates service work and reduces the time required for replacement. With correct installation, stable window operation and proper adhesion to the seals are achieved.

In daily use, a correctly selected window regulator mechanism affects:

• comfort of window operation by rear seat passengers,
• maintenance of door tightness in the window area,
• reduction of noise resulting from improper window closing,
• trouble-free cooperation with comfort systems, if present in the vehicle.

Product condition and practical application

The offered element is in used condition, which allows for an economical restoration of the window system's efficiency while maintaining the manufacturer's original specifications. This solution is particularly beneficial for repairs of vehicles used intensively, where a reasonable service cost while maintaining appropriate quality is important.

Choosing a used window regulator mechanism is consistent with the approach to other vehicle components, such as power units or drivetrain elements. You can find more about how to consciously approach the purchase of used technical components in the article Why it is worth buying used gearboxes and engines – facts instead of myths, which discusses the practical aspects of selecting parts by manufacturer markings and real cost benefits.

Expanding repairs within the window system

If you are planning a comprehensive repair or upgrade of the side window area in your Mercedes and need other elements from the same group, such as guides, regulator motors, or additional control mechanisms, check the available parts in the Mercedes window regulators and motors category.