First, to service and repair rear upper control arm, raise and support the vehicle. If equipped, remove the Real Time Damping (RTD) sensor. Use the wrench mobility to remove the upper control arm retaining nut and bolt from the frame bracket, remove of the retaining nut and bolt from the axle bracket, then the upper control arm is removed. For installation, start with the upper control arm at the position and install the retaining bolt and nut to the axle bracket, then install the retaining bolt to the frame bracket. It is very important not to tighten nuts until you are at the curb height in the suspension. When you've fixed the upper control arm retaining nut, tighten the retaining bolts to 105 Nm(77 ft. lbs.); Last but not least, reconnect the RTD sensor where available and return the vehicle to the ground.