Check the dust seals and verify if they are fractured or brittle and change them in case of necessity. Test end play of upper and lower ball joints, when either has a play over 0.10mm (0.0039 in.), it is deemed flawed. On cars 1972-1984, front lift On jackstands under the frame, then use a floor jack to raise the lower control arm until the upper control arm is clear of the bumper stop. Take out the wheel, insert a chain into the coil spring to be sure, or apply a spring compressor and take out the cotter pin and nut that held the upper ball joint. Disconnect the ball joint to the spindle with a ball joint separator, unscrew the two upper arm retaining bolts and pull the arm off of the truck, counting and recording the location of any shims. Unscrew and remove the ball joint of the arm, and in installing, put the shims in their original position, and torque the two arm retaining bolts to 65-75 ft. lbs., the ball joint-to-arm bolts to 15-20 ft. lbs and the ball joint-to-spindle nut to 40-55 ft. lbs. To work with vehicles of 1986-89, elevate and stabilize the front part of the vehicle on jackstands below the frame, take off the wheels, and stabilize the lower arm on a floor jack. Unscrew the cotter pin and the nut on the upper ball joint and then disassemble the knuckle using a ball joint separator tool. Take the bushings and dust seals off the ends of the upper arm shaft and the nuts and bolts fastening the upper arm shaft to the support bracket and record the number and position of the shims to have the proper alignment of the wheels. Inspect all components of the parts that may be worn or damaged and substitute any suspect component. Measure the ball joint preload using a pull scale and adapter and the result must be 40 lb. or less. Unscrew and unbolt the ball joint out of the arm and during the installation screw the upper arm shaft mounting bolts to 60-68 ft. lbs., the ball joint-to-arm bolts to 15-20 ft. lbs. and the ball joint nut to 30-37 ft. lbs.