Gearbox Flywheel Mercedes W221 OM629 OM642 Starter Ring Automatic A6290300312

Mercedes W221 OM642 Flywheel A6290300312 is a component from the flywheels and gears category, designed to work with the OM642 engine and automatic transmission in the S-Class W221 model. This used genuine part ensures proper torque transfer, stable drivetrain operation, and correct interaction with the automatic gearbox. It's a solution for users seeking a technically matched flywheel for a specific engine-transmission configuration.

Specifications and technical data

• SKU: A6290300312
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6290300312
• Substitutable numbers: A6290300312, A 629 030 03 12
• Gearbox type: Automatic
• Category: Flywheels & Flexplates

Purpose and Technical Fitment

The flywheel is dedicated to the OM642 engine in the W221 body, with a factory automatic transmission. Its design is tailored to the specific operating parameters of the diesel unit and the gearbox characteristics, which translates to:

• proper damping of crankshaft torsional vibrations,
• stable load transfer during gear changes,
• maintaining the driving refinement typical for the S-Class.

By retaining its original geometry and mounting points, the flywheel works with the factory starting system and automatic transmission components, reducing the risk of installation issues.

Operating Characteristics with Automatic Transmission

In vehicles with an automatic transmission, the flywheel plays a crucial role in smoothly transferring torque to the torque converter. In this application, the following are important:

• appropriately selected mass and stiffness, influencing smooth starts and reducing jerks,
• precise balancing, which minimizes vibrations transmitted to the body,
• compatibility with the factory bolt pattern for the torque converter and starter ring gear.

A flywheel configured in this way helps maintain stable idle speed, improves gear-shifting comfort, and supports long-term, predictable operation of the automatic transmission.

Benefits of Using a Genuine Mercedes Flywheel

Using a genuine flywheel in the W221 drivetrain with the OM642 engine allows for the preservation of the unit's factory operating parameters. The most significant advantages include:

• Full Structural Compatibility – maintaining proper fitment with the crankshaft, torque converter, and gearbox housing.
• Predictable Drivetrain Behavior – no need for adaptation or modification of control software.
• Consistency with Other System Components – the flywheel works with the factory starter and engine accessories, facilitating diagnostics and servicing.

This solution is particularly beneficial for drivetrain repairs where maintaining the vehicle manufacturer's specified parameters is crucial.

Condition, Verification, and Practical Application

The offered flywheel is a used part from a dismantled vehicle, allowing for economical repair while maintaining original specifications. Before reinstallation, a standard workshop inspection is recommended, including an assessment of the working surfaces, starter ring gear, and mounting points. In practice, the installation of this type of component is carried out by workshops specializing in the Mercedes brand, which facilitates adherence to the correct service procedure.

Mercedes Flywheels and Gears – Part Selection

If you are looking for other Mercedes flywheels and gears matched to specific models and engine versions, use our dedicated category: Mercedes flywheels and gears. This will allow you to easily compare available solutions and select a part that matches your car's configuration.

Used Parts vs. Drivetrain Tuning and Modernization

The flywheel from the OM642 unit can be used not only for standard repairs but also in modernization projects where maintaining the factory operating characteristics of the engine and transmission is important. For more extensive modifications, it is worth consulting the guide on selecting used parts – especially for projects involving the combination of different drivetrain configurations. You can find more practical tips in the article: Best Used Parts for Tuning Your Car, which discusses how to consciously use used components in tuning and modernization projects.