This bulletin applies to 2013-2015 Cadillac XTS vehicles equipped with Performance Strut Assembly (RPO GNB). Some customers may comment on a click, pop or clunk noise from the front suspension during braking, over bumps at low speeds and/or when turning. This may be caused by a loss of clamp load at the lower revolute joint (King pin bushing) at the knuckle attachment.
To inspect the torque on the king pin bushing nuts, remove the front suspension lower control arm and inspect nut torque. If torque is not at least 45 ft-lb, replace the king pin bushings and nuts for both strut assemblies. Torque the new nuts once, then remove the nuts and apply liquid thread locker P/N 89021297 to the king pin bushing studs. Once verified that the studs are fully seated, re-torque the nuts to 74 ft-lb.
New nuts are available as P/N 11546367. Front suspension strut yoke lower ball joints are available as P/N 23275106.
