Genuine OEM Volkswagen Differential Housing, part number 0AH409021P. This is the main casing that encloses and protects the internal components of the differential assembly. It is crucial for maintaining the correct alignment of gears and bearings. Constructed from robust cast aluminum, it ensures durability and resistance to operational stresses. The precise engineering of this housing is vital for the smooth and efficient operation of the drivetrain, preventing leaks and contamination.