Owners of 2021 Mercedes-Benz vehicles with front wheel drive (and 4x4 vehicles) may complain about a single throttle lift-off clunk noise when changing from forward to reverse or reverse to forward.
The noise is likely coming from the side shaft outboard end. If the complaint is eliminated by experimentally loosening the outboard collar nut by one turn, the concern is due to micro-movement in the connection between the wheel bearing inner race and the joint housing of the side shaft.
Note: the collar nut must always be replaced after being loosened and must be tightened to the specified torque.
Coat the contact surface of the side shaft with wheel bearing with Molykote low-friction paint P/N A0009890152. Remove the outboard side shafts (extract the outer joint gearing from the wheel hub before applying Moykote).
Make sure the surface is free of dust and grease. Stir or shake the paint thoroughly. Coat the contact surface with Molykote and allow the paint to dry for at least one hour in removed condition.
