GMC 1982 Light Duty Truck Service Manual page 362

3 C -2 0 FRONT SUSPENSION
Fig. 3C-27--Disconnecting Ball Joints-Typical
BALL JOINT SERVICE-ON VEHICLE
Ball Joint-lnspection
The upper ball stud is spring loaded in its socket. This
minimizes looseness at this point and com pensates for
normal wear, if the upper stud has any perceptible lateral
shake, or if it can be twisted in its socket with the fingers, the
upper ball joint should be replaced.
Upper-Removal
1. Raise vehicle on hoist. If a frame hoist is used, it will be
necessary to support the lower control arm with a floor
jack.
2. Remove cotter pin from upper ball stud and loosen stud
nut (two turns) but do not remove nut.
3. Install J-23742 between the ball studs as shown in
Figure 3C-27.
It is necessary to remove the brake caliper assembly
and wire it to the frame to gain clearance for tool
J-23742. See section 5 for the proper procedure.
4. Be sure lower control arm is supported as pointed out in
step 1. Extend bolt from Tool J-23742 to loosen ball
stud in steering knuckle. When stud is loose, remove
tool and stud nut.
5. Center punch rivet heads and drill out rivets.
6. Remove the ball joint assembly.
Installation
NOTICE: See N O T I C E on page 1 of this section
regarding the fasteners referred to in steps 1, 3 and 6.
Fig. 3C -28--C otter Pin Installation
1. Install new service ball joint, using bolts and nuts
supplied with joint, to upper arm. Torque nuts to 60
N-m (45 ft. lbs.).
2. Mate ball stud to steering knuckle and install stud nut.
3. Torque the ball stud nut as follows:
A. 10 Series 54-80 N-m (40-60 ft. lbs.) plus additional
torque to align cotter pin not to exceed 120 N-m (90
ft. lbs.). Never back off to align cotter pin.
B.20-30 Series 110-140 N-m (80-100 ft. lbs.) plus
additional torque to align cotter pin not to exceed
175 N-m (130 ft. lbs.) Never back off to align cotter
pin.
4. Install new cotter pin as shown in Figure 3C-28.
5. Install lube fitting and lube new joint.
6. Install brake caliper assembly if removed (see section
5).
7. Install tire and wheel assembly.
8. Lower the vehicle to the floor.
Ball Joint-lnspection
Lower
Lower ball joints are a loose fit when not connected to
the steering knuckle. W ear may be checked without disas­
sembling the ball stud, as follows:
1. Support weight of control arms at wheel hub and drum.
2. Accurately measure distance between tip of ball stud
and tip of grease fitting below ball joint.
3. Move support to control arm to allow wheel hub and
drum to hang free. Measure distance as in Step 2. If the
difference in measurements exceeds 2.38 mm (.094"
(3 /3 2 " ) for all models, ball joint is worn and should be
replaced (Fig. 3C-29).
Lower-Removal
1. Raise vehicle on a hoist. If a frame hoist is used it will
be necessary to support the lower control arm with a
floor stand.
2. Remove the tire and wheel assembly.
3. Remove the lower stud cotter pin and loosen (two
turns) but do not remove the stud nut.
Fig. 3C-29--Checking Lower Ball Joint