This bulletin applies to 2011-2017 and 2019-2025 Audi A8, 2012-2025 A6/A7, 2013-2016 and 2020-2025 S6/S7, 2013-2016/2020-2025 S6 and S7, 2014-2016 and 2021-2025 RS7, 2017-2025 A4/Q7, 2018-2025 S4/A5/S5, Q5/SQ5, 2018-2019 RS5, 2021-2025 RS5, and 2019-2025 Q8 vehicles.

The customer may complain about sporadic rattling/clacking noises from the front axle when rolling slowly (less than 12 mph) over curbs or on uneven road surfaces. Be aware that it does not make sense to investigate noises at temps below 32 deg F, because all rubber bushings in the running gear are hard due to cold conditions.

The noises may be made by the guide link hydro-bushings. The bushings feature air bubbles inside the bushings during manufacturing. When vibrations are induced in the axle by uneven road surfaces, the high frequency change in bushing internal pressure causes the volume of the air bubbles to change, which can produce rattling/clacking noises. The air bubble inside the bushing enables a decoupling from micro-amplitudes which improves the vehicle’s interior acoustics. It also has a positive effect on steering behavior. In other words, the noises are normal.