Mercedes W204 Gearbox Oil Cooler Hose Left N/S OM646 Automatic Transmission

Mercedes W204 D Transmission Oil Line Left is an original part from the automatic transmission parts category, designed for the gearbox system in diesel-powered vehicles. A used oil line helps maintain the gearbox's factory operating characteristics, ensuring stable pressure and proper lubrication of components.

Specifications and technical data

• SKU: A6461801730
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6461801730
• Substitutable numbers: A6461801730, A 646 180 17 30, BG
• Location on the vehicle: Left
• Fuel type: Diesel
• Gearbox type: Automatic
• Category: Automatic Transmission Parts

Purpose and Function of the Transmission Oil Line

The left transmission oil line in Mercedes C-Class W204 models with a diesel engine is responsible for transporting working oil between the components of the automatic transmission system. A correctly selected and sealed line:

• maintains a stable oil flow in the gearbox's cooling and lubrication circuit,
• reduces the risk of automatic transmission overheating during city and highway driving,
• supports smooth gear changes and overall transmission performance.

By maintaining its original geometry and internal diameter, the line works seamlessly with the factory hydraulic system, promoting predictable gearbox behavior during acceleration and downshifts.

Compatibility with Diesel Powertrain and Automatic Transmission

This part is designed for vehicles with a diesel engine and an automatic transmission. This configuration requires a line resistant to:

• variable operating temperatures of the transmission oil under loads typical for diesel engines,
• pressures generated by the automatic transmission's hydraulic system,
• long-term operation in road conditions typical for premium mid-size cars.

By being tailored to a specific powertrain, the line helps maintain stable transmission operating parameters, leading to predictable vehicle behavior and reduced risk of leaks at critical points in the system.

Vehicle Placement and Installation Aspects

The line is designed for installation on the left side of the vehicle, following the factory routing of the oil system in the Mercedes W204. Proper positioning relative to the body and other powertrain components:

• minimizes mechanical stress and vibrations acting on the line,
• reduces the risk of abrasion against suspension or body components,
• facilitates servicing and leak checks during inspections.

Correct fitment to original mounting points ensures installation in accordance with manufacturer recommendations, without the need for system modifications.

Benefits of Using an Original Oil Line

Using an original transmission oil line for the Mercedes W204 offers a range of practical benefits:

• Factory Fitment – compatibility with the automatic transmission's hydraulic and cooling system.
• Stable Operating Parameters – maintaining proper transmission oil flow under typical operating conditions.
• Reduced Risk of Failure – decreasing the likelihood of leaks and pressure drops in the system.
• Vehicle Design Consistency – preserving original line routing and service ergonomics.

How to Verify Compatibility by VIN and OEM Number

To ensure the left transmission oil line is suitable for your specific Mercedes model, it is advisable to compare your vehicle's details (especially the VIN) and the part's markings in the manufacturer's catalog before purchasing. A detailed guide, which describes step-by-step how to check part compatibility using catalog numbers and technical parameters, can be helpful – you can find it here: Guide: How to Select the Right Car Part by VIN and OEM Number.

Other Parts for Mercedes Automatic Transmissions

If you are also looking for other Mercedes automatic transmission parts, check out our dedicated offer: Mercedes automatic transmission parts. This will allow you to easily assemble the components needed for a comprehensive service of your car's gearbox.