GM Full-Size Trucks 1970-1979 Repair Guide

Upper Ball Joints

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INSPECTION



  1. Raise and support the truck so that the control arms hang free.
  2.  
  3. Remove the wheel.
  4.  
  5. Support the lower control arm with a jacking stand and disconnect the upper ball stud from the steering knuckle.
  6.  
  7. Reinstall the nut on the ball stud and measure the torque required to rotate the stud. If the torque is not within 1-10 ft. lbs. (1.4-13.5 Nm), replace the ball joint.
  8.  
  9. If no defects are evident, connect the steering knuckle to the upper stud and tighten to 70 ft. lbs. (95 Nm). Tighten further to install the cotter pin, but don't exceed 90 ft. lbs. (122 Nm).
  10.  

REMOVAL & INSTALLATION



2-Wheel Drive
  1. Raise and support the truck with jackstands. Remove wheel.
  2.  
  3. Support the lower control arm with a floor jack.
  4.  
  5. Remove the cotter pin from the upper ball stud and loosen, but do not remove the stud nut.
  6.  
  7. Using the special tool or its equivalent, loosen the ball stud in the steering knuckle. When the stud is loose, remove the tool and the stud nut. It may be necessary to remove the brake caliper and wire it to the frame to gain clearance.
  8.  
  9. Drill out the rivets. Remove the ball joint assembly.
  10.  

To install:
  1. Install the service ball joint, using the nuts supplied or special hardened fasteners.
  2.  
  3. Torque the ball stud nut as follows:

    1 / 2 ton trucks: 60 ft. lbs. (81 Nm) plus the additional torque to align the cotter pin. Do not exceed 90 ft. lbs. (122 Nm) and never back the nut off to align the pin.
     
    3 / 4 and 1 ton trucks: 80-100 ft. lbs. (108-136 Nm) plus additional torque necessary to align the cotter pin. Do not exceed 130 ft. lbs. (176 Nm) and never back off the nut to align the pin.
     

  4.  
  5. Install a new cotter pin.
  6.  
  7. Install a new lube fitting and lubricate the new joint.
  8.  
  9. If removed, install the brake caliper.
  10.  
  11. Install the wheel and lower the truck.
  12.  

4-Wheel Drive

See Figures 1, 2, 3 and 4



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Fig. Fig. 1: Remove the steering arm nuts and replace with new ones during installation



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Fig. Fig. 2: On 4-wheel drive vehicles, remove the ball socket retaining nuts



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Fig. Fig. 3: Press the lower ball joint out of the knuckle



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Fig. Fig. 4: Upper ball joint removal - 4-wheel drive trucks

The steering knuckle pivot ball joints may need replacement when there is excessive steering play, hard steering, irregular tire wear (especially on the inner edge), or persistent tie rod loosening.

This procedure requires the removal of the steering knuckle before the ball joints can be removed. K30 models use kingpins. Refer to the procedure later in this section for these models.

  1. Support the front axle on jackstands.
  2.  
  3. Remove the axle shaft as detailed earlier.
  4.  
  5. Remove the steering linkage. The best method is to use a tie rod end puller.
  6.  
  7. If you remove the steering arm from the top of the knuckle, the nuts cannot be reused.
  8.  
  9. Remove the cotter pin and ball joint stud nuts.
  10.  
  11. Remove the knuckle from the housing yoke by forcing a wedge between the lower ball stud and the yoke, then between the upper ball stud and the yoke.
  12.  


WARNING
If you have to loosen the upper ball stud adjusting sleeve to remove the knuckle, don't loosen it more than two threads. The soft threads in the yoke are easily damaged.

  1. Remove the lower ball joint snapring. Press the lower ball joint out first.
  2.  
  3. Press out the upper ball joint and unscrew the adjusting sleeve. A spanner wrench is required for the sleeve.
  4.  
  5. Press the new lower ball joint into the knuckle and install the snapring. The lower joint doesn't have a cotter pin hole.
  6.  
  7. Press the upper ball joint into the knuckle.
  8.  
  9. Position the knuckle to the yoke. Install new stud nuts finger tight.
  10.  
  11. Push up on the knuckle and tighten the lower nut to 70 ft. lbs. (95 Nm).
  12.  
  13. Using a spanner wrench, install and tighten the upper ball stud adjusting sleeve to 100 ft. lbs. (136 Nm) and install the cotter pin. Don't loosen the castellated nut, but make it tighter to line up the cotter pin hole.
  14.  
  15. Replace the steering arm, using new nuts and torquing to 90 ft. lbs. (122 Nm).
  16.  
  17. Check the knuckle turning torque with a spring scale hooked to the tie rod hole in the steering arm. With the knuckle straight ahead, measure the right angle pull to keep the knuckle turning after initial breakaway, in both directions. The pull should be 25 lbs. (111 N) or less for axles assembled after Feb. 10, 1976, and 33 lbs. (147 N) for earlier models.
  18.  
  19. Replace the axle shaft and other components. Tighten the steering linkage nuts to 45 ft. lbs. (61 Nm).
  20.  

 
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