This procedure applies to both 2WD and 4WD models. If the vehicle is equipped with air suspension, turn off the air suspension system. The switch is located in the area of the right kick panel. Measure the height of the center of the hub to the ground before proceeding. Loosen the wheel lug nuts, raise the front of the vehicle and support it securely on jackstands. Remove the wheel. Position a floor jack, with a wood block on the jack head (to act as a cushion), under the lower control arm in the area between the spring seat and the balljoint. Raise the jack slightly to take the spring pressure off the upper control arm. Mark the position of the upper control arm camber adjustment cam. If the vehicle is equipped with a 4-wheel anti-lock brake system (4WABS), remove the bracket bolt for the wheel speed sensor wire and place the sensor wire out of harm's way. To disconnect the upper control arm from the steering knuckle, remove the cotter pin from the balljoint castle nut, loosen the nut a few turns (don't remove it), install a small puller and break the balljoint loose from the knuckle. Now remove the nut. Remove the upper control arm pivot bolts and nuts. Remove the control arm. Inspect the pivot bolt bushings for wear. If the bushings are worn, you'll have to replace the control arm. Inspect the upper balljoint seal. If it's leaking, replace the control arm. The balljoint is not serviceable. Position the arm in the frame brackets and install new bolts and nuts. They must be installed with their heads facing toward each other. Make sure the marks you made prior to disassembly are aligned, then tighten, but don't torque, the pivot bolt nuts. Attach the balljoint to the steering knuckle and tighten the ballstud nut. Reattach the 4WABS front brake anti-lock sensor wire bracket and tighten the bolt securely. Install the wheel and lug nuts, then lower the vehicle. Tighten the lug nuts. Tighten the upper arm pivot bolt nuts, front nut first. Reactivate the air suspension system, if equipped.