This transmission mount is designed for the A8 D3 4.2 V8 models manufactured between 2004 and 2010.It serves as a replacement component compatible with part numbers 4E0399151DD, 4E0399151CE, 4E0399151AR, and 4E0399151AQ.The unit fits either the left or right side of the transmission assembly.Its primary function is to secure the transmission to the vehicle frame and dampen vibrations generated by the engine and drivetrain during.Replacement is recommended if the mount shows signs of wear, such as excessive vibration, knocking noises during gear shifts, or visible damage to the mounting hardware.This component is engineered to match the specifications for fit and function, ensuring proper alignment of the transmission system.Installation requires lifting the vehicle and removing the existing mount before securing this unit in place according to standard torque specifications.This item is intended solely for use with the specified A8 D3 4.2 V8 model years and engine configuration.