Audi A8 D4 Window Lifter Regulator Rear Left N/S Door 4H0839461B

Audi A8 D4 Window Lifter Regulator Rear Left N/S Door is an original component from the Window regulators and motors group, designed for precise operation of the window in the rear left door. It ensures stable window guidance, proper cooperation with the control mechanism, and maintains the factory functionality of the window opening and closing system.

Specifications and technical data

• SKU: 4H0839461B
• Mark: Audi
• Condition: Used
• OEM Part Number: 4H0839461B
• Substitutable numbers: 4H0839461B, 4H0 839 461 B, 1021-918640-105
• Location on the vehicle: Rear, Left
• Category: Window Motors & Regulators

Purpose and function in the vehicle

The window regulator in the Audi A8 D4 model is responsible for the smooth raising and lowering of the window in the rear left door, while maintaining proper guidance within the tracks. This component works with the vehicle's electrical system and controls from the door panel and console, which is important for the comfort of the driver and passengers.

Thanks to the factory fitment for the Audi body, the mechanism maintains the correct operating geometry, which reduces the risk of jamming, excessive play, or uneven window closing. This is particularly important in luxury class vehicles, where quiet operation and a repeatable, predictable response to every impulse from the control button are expected.

Construction and mounting fitment

The regulator is structurally prepared for installation in the rear left area of the body, taking into account the specific door construction of the Audi A8 D4. The layout of mounting points, guides, and components interacting with the window is consistent with the manufacturer's factory specifications, which facilitates installation and allows for maintaining the original window operating line.

The appropriate structural rigidity and proper guidance of the cable or arm (depending on the version) influence the even distribution of loads during operation. As a result, the window moves stably without excessive vibrations, which translates into less wear on seals and guide elements.

Benefits of using an original regulator

Using an original Audi solution for the window mechanism allows for maintaining the consistency of the entire door system. Key advantages include:

• factory fitment to the door and window construction,
• proper cooperation with the electrical system and controls,
• stable window operation throughout the full range of motion,
• reduced risk of improper closing or window misalignment.

For workshops and users, this means shorter installation time, fewer adjustments after installation, and greater predictability of operation in the long term.

Characteristics of the used product

The item comes from dismantling, which allows for an economical restoration of the window lifting system's efficiency while maintaining the original Audi specification. For many users, this is a reasonable compromise between the cost of repair and maintaining the factory standard of workmanship.

When selecting a used regulator, it is particularly important to verify compatibility with the vehicle using the OEM part number and interchangeable numbers – this information can be found in the technical specifications section. This helps to reduce the risk of purchasing a component with a different mounting layout or different operating parameters.

Audi window regulators and motors – expansion and service

If you are planning a comprehensive repair or upgrade of the door area in your Audi and need other elements from the same group, such as window lifting mechanisms, electric drives, or complete guide modules, check the available parts in the Audi window regulators and motors category.

Support with selection and additional materials

When purchasing a used window regulator, it is worth paying attention to compatibility with the vehicle's equipment and the part's service history. Practical tips on the safe selection and verification of components from the secondary market can be found in the guide Safe purchase of used car parts online – a step-by-step guide.

If you are also interested in issues related to the operation and potential problems of engines in other brands, the article BMW E90 engine failures: check what can ruin your budget! may be helpful, as it shows how a conscious approach to service affects the total cost of car maintenance.