Audi A4 B8 Rear Door Window Lifter Regulator Mechanism Left N/S 8K0839461C

Audi A4 B8 Rear Door Window Lifter Regulator Mechanism Left N/S is an original component from the Window Regulators and Motors group, designed for the rear left window in the Audi body. It ensures stable window operation, proper guidance within the rails, and secure closing, which translates into daily comfort and the correct functioning of the electric window system.

Specifications and technical data

• SKU: 8K0839461C
• Mark: Audi
• Condition: Used
• OEM Part Number: 8K0839461C
• Substitutable numbers: 8K0839461C, 8K0 839 461 C
• Location on the vehicle: Rear, Left
• Part type: Window Regulator
• Category: Window Motors & Regulators

Purpose and function in the Audi A4 B8

The window regulator mechanism is responsible for precise raising and lowering of the window in the rear left door, working in conjunction with the factory window controls in the Audi. A correctly selected component guarantees smooth window movement without jamming, minimizes the risk of misalignment, and reduces the load on the electrical system and the comfort control module.

Its placement in the rear left zone allows for the direct replacement of a damaged mechanism without interfering with other doors, which shortens service time and facilitates the diagnosis of any faults related to window operation.

Construction and technical properties

The mechanism is designed as a complete working unit, ready for installation within the inner door structure. The applied design solutions ensure:

• stable window guidance throughout the entire range of operation,
• proper power transmission from the motor to the window,
• maintenance of the correct mounting geometry within the door,
• compatibility with the factory Audi window control system.

As a result, the mechanism works with the original mounting points in the door, which facilitates installation and reduces the need for additional adjustments after replacement.

Benefits of using an original mechanism

Using a dedicated window regulator mechanism in the Audi A4 B8 brings a number of practical operational benefits:

• Proper fit to the door structure – maintaining factory mounting clearances and correct alignment with the window.
• Compatibility with the existing electrical system – no need for wiring or control modifications.
• Reduction of noise and vibration during window operation – improvement of acoustic comfort inside the vehicle.
• Ability to restore full window functionality after mechanical failure or wear and tear.

The component from this group is particularly important in vehicles used daily, where frequent opening and closing of windows requires stable and repeatable system performance.

Condition, installation, and service application

The offered mechanism comes from a used vehicle, which allows for economical repair while maintaining original Audi specifications. This solution is recommended in situations where cables, guides, or gears have been damaged, as well as for symptoms such as uneven window movement, jamming, or lack of response to controls.

During installation, it is recommended to:

• verify the condition of the window and door seals,
• check the correct operation of the window control switch,
• inspect the electrical wiring in the door for abrasions and kinks.

Such a service approach helps avoid repeated removal of the door trim and shortens the time of any potential future repairs.

Audi Window Regulators and Motors – expansion and door zone service

If you are planning a comprehensive repair or upgrade of the door zone in your Audi and need other components from the same group, such as additional regulator mechanisms, window drives, or related control elements, check the available parts in the Audi Window Regulators and Motors category.

Technical support and service knowledge

When planning repairs for premium class cars, it is worth knowing the typical weak points of individual models and engine units to better plan your service budget. The guide Faulty BMW E90 engines: check what can ruin your budget! may be helpful, as it shows how a conscious approach to operation and repairs allows for reducing unforeseen costs – the same principles should be applied when servicing Audi vehicles, including window systems and door equipment.