This is a Quality Bulletin. Volvo Car USA LLC and Volvo Car of Canada Ltd (Volvo) on behalf of Volvo Car Corporation, has decided to launch Service Campaign S49792 on certain model year 2016 XC90 vehicles. Volvo has identified that certain vehicles may have been manufactured with axle shaft boots that are out of specification. This can result in water and dirt ingress into the axle shaft boot and grease leakage over time. The corrective action is to replace both rear axle shafts.