Mercedes ML W166 4Matic Rear Axle Differential Diff I=3.27 A1663504214 WARRANTY

Listing details

The differential is sold with a 90-day warranty! It was tested before removal and is in full working order.

Mercedes ML W166 4Matic Rear Axle Differential Diff I=3.27 is an original drivetrain component designed for the rear axle in vehicles equipped with 4Matic all-wheel drive and a diesel engine. This rear differential ensures stable torque distribution, which translates into predictable handling and safe traction during daily operation. It is the ideal solution for users who expect factory compatibility, consistency with vehicle electronics, and the maintenance of the correct axle gear ratio.

Specifications and technical data

• SKU: A1663504214
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1663504214
• Substitutable numbers: A1663504214, A 166 350 42 14
• Location on the vehicle: Rear
• Fuel type: Diesel
• Part type: Differential & Housing Assembly
• Category: Differentials

Purpose and function of the rear differential

The presented rear differential is a component of the drivetrain in Mercedes vehicles with 4Matic drive, operating with a diesel engine. It is responsible for transferring power to the rear wheels while maintaining the correct gear ratio, which is crucial for proper interaction with the front-wheel drive, transmission, and safety systems (including traction control and electronic stability control).

Selecting a differential with the correct gear ratio is particularly important in four-wheel-drive vehicles – an incorrect axle can cause stress in the drivetrain, electronic system errors, and accelerated wear of components. Using a dedicated differential allows for the preservation of factory characteristics regarding acceleration, engine RPM, and driving comfort.

Benefits of using an original rear differential

Choosing an original rear differential for the Mercedes ML W166 4Matic offers a number of practical advantages:

• preservation of the factory axle gear ratio and proper interaction with the 4Matic system,
• consistency with factory settings of control units and driver assistance systems,
• proper fitment to the rear suspension and axle shaft design,
• reduction of the risk of vibrations, noise, and uneven tire wear.

As a result, the driver receives stable vehicle handling, predictable behavior on slippery surfaces, and correct cooperation with ABS/ESP systems. This is especially important in heavier SUVs, where the loads acting on the drive axle are higher than in passenger cars.

Application in diesel engine vehicles

The differential has been designed to work with diesel units that generate high torque even at low engine speeds. This requires a properly selected gear construction to ensure:

• smooth torque transfer without jerking,
• adequate gear tooth strength under high loads,
• stable operation across a wide range of loads – from city driving to highway cruising.

A rear differential configured in this way allows for the full potential of the diesel engine to be utilized while protecting other drivetrain components.

Condition, installation, and selection by part numbers

The offered item comes from the Differentials category and is intended for reinstallation in a vehicle. Before installation, a standard service procedure is recommended: checking for leaks, play, the condition of mounts, and changing the axle oil according to the vehicle manufacturer's recommendations. Proper installation should be performed by a workshop experienced in working with 4x4 drivetrains, which minimizes the risk of subsequent operational irregularities.

To ensure that the selected differential is compatible with your specific version of the Mercedes ML W166, it is worth verifying compatibility using part numbers and vehicle data. A detailed guide describing the selection of axles and final drives may be helpful – you can find it in the article Dismantled drive axles and differentials – how to choose gear ratios for your driving style, where issues such as gear ratios, compatibility, and practical application examples are discussed.

If you want to further minimize the risk of errors when purchasing online and learn methods for verification via OEM numbers, the guide purchasing parts by OEM numbers for Mercedes and other brands will be useful, describing step-by-step how to check component compatibility before finalizing an order.

Expanding the drivetrain in a Mercedes

If you are planning a comprehensive repair or upgrade of the drivetrain area in your Mercedes and need other elements from the same group, such as other axles, final drives, or additional differentials, check the available parts in the Mercedes Differentials category.

This approach allows for the consistent renewal of the entire drivetrain, which is particularly important in vehicles used for towing, off-road, or on long journeys. Replacing several related components in one service stage often reduces future vehicle downtime and improves the overall refinement of the drivetrain.