Genuine OEM Audi Flange Nut, part number 086307303. This high-strength fastener is used to secure components within the transmission and drivetrain assembly. It is designed to withstand the specific torque and vibration requirements of the drivetrain environment. Using genuine OEM fasteners is essential for ensuring the correct thread pitch, material hardness, and clamping force, which are critical for preventing component loosening and ensuring the long-term durability of the transmission assembly.