Mercedes W221 Gearbox Cooler Oil Transmission Radiator Right O/S A6421800831

Mercedes W221 Gearbox Cooler Oil Transmission Radiator Right O/S is an original lubrication system component designed for precise oil delivery to the radiator on the right side of the vehicle. This used component from the Oil coolers and lines group allows for a technically sound repair without the need for aftermarket replacements with uncertain parameters. It is a practical solution for users who want to restore proper oil cooling in their Mercedes while maintaining factory engine performance characteristics.

Specifications and technical data

• SKU: A6421800831
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6421800831
• Substitutable numbers: A6421800831, A 642 180 08 31
• Location on the vehicle: Right
• Category: Engine Oil Coolers & Lines

Purpose and function of the oil cooler line

The right-side oil cooler line in the Mercedes S-Class W221 generation is responsible for a stable connection between the oil cooler and the other components of the lubrication system. A correctly selected hose ensures:

• controlled oil flow in the cooling circuit,
• maintenance of the proper operating temperature of the power unit,
• reduction of the risk of oil overheating under high engine load.

Thanks to the preservation of factory geometry and the correct positioning on the right side of the vehicle, this component works with other system parts without the need for modifications.

Benefits of using an original Mercedes line

Choosing an original oil cooler line for the Mercedes W221 is a solution that technically supports long-term and stable engine operation. The most important advantages include:

• Factory fitment – the correct length, diameter, and shape of the line facilitate installation at original mounting points.
• Consistency with the oil cooling system – the line works with the factory oil cooler and other lines in the same section.
• Reduced risk of leaks – properly selected ends and profile of the line help maintain connection tightness when operating under pressure.

A component configured in this way allows for maintaining predictable lubrication system operating parameters, which is especially important in premium class cars such as Mercedes.

Application in service practice

The right-side oil cooler line is particularly important for repairs related to:

• oil leaks in the area of the oil cooler,
• mechanical damage to lines in the front part of the vehicle,
• modernization or replacement of oil cooling system components.

Replacing a worn line with an original component from the same group allows for restoring proper oil circulation and reducing the thermal load on the engine. This is particularly important in urban and highway operation, where the oil cooling system works under varied conditions.

Technical support and knowledge about the cooling system

To better understand the impact of the oil cooler and lines on the durability of the power unit, it is worth checking out the guide on diagnostics and operation of the cooling system – a detailed discussion can be found in the article Engine cooling system – overheating, repair, and used radiators. This is a practical supplement to your knowledge when planning repairs in a Mercedes S-Class.

Expanding repairs within the oil cooling system

If you are planning a comprehensive repair or modernization of the engine area in your Mercedes and need other elements from the same group, such as additional lines, supply pipes, or oil cooler connection elements, check the available parts in the Mercedes oil coolers and lines category.