See Figure 1
With the control arm removed, check the starting torque required to turn the ball stud. Install the nut back onto the ball stud. Then, with an inch lb. torque wrench, measure the torque required to start the ball joint rotating. The specification for all models is 7-30 inch lbs. (0.8-3.5 Nm). If the ball joint fails this check, replace the ball joint on 1979-86 models, or replace the upper control arm assembly on 1987-93 models.
REMOVAL & INSTALLATION
See Figures 2, 3, 4 and 5
The upper ball joint and upper control arm must be replaced as an assembly on 1987-93 Pick-ups.
- Elevate the vehicle and support it safely on jackstands.
- Remove the upper control arm-refer to the procedures in this section.
- Remove the ring and boot (dust cover) from the ball joint.
- Remove the snapring from the upper ball joint by using a pair of snapring pliers.
- Press the upper ball joint out of the upper control arm by using tools MB 990800-2-01, MB 990800-3-01, MB 990800-4-01 and MB 990799-01, or equivalent installing tools.
A minimum of 2200 lb. (9800 N) of pressure will be required to remove the ball joint from the control arm.To install:
- Align the mating mark on the upper ball joint with the upper arm center line.
- Press the ball joint in using the same tools that were used to remove the ball joint.
- Using a pair of snapring pliers, fit the snapring securely in the groove of the joint case. If the snapring is loose, install a new one.
Limit the opening of the snapring to a minimum.
- Apply the multipurpose grease to both the interior of the dust cover and the upper ball joint. Apply 3M ART Part No. 8663 or equivalent sealant to the grooves in the upper ball joint. Secure the dust cover to the upper ball joint with a ring.
- Install the upper control arm-refer to the procedures in this section.
- Lubricate the ball joint with a grease gun.
- Adjust the riding height if equipped with a torsion bar and align the front end.