GM Full-Size Trucks 1988-1998 Repair Information

Lower Control Arm and Bushing

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REMOVAL & INSTALLATION



See Figures 1, 2 and 3

Special tools J-36202, J-36618-1, J-36618-2, J-36618-3, J-36618-4, J-36618-5, and J-9519-23, or their equivalents, are necessary for this procedure.

  1. Raise and support the truck on jackstands.
  2.  



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Fig. Fig. 1: Disconnect the tie rod end from the steering knuckle



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Fig. Fig. 2: Matchmark the torsion bar adjustment bolt positions

  1. Remove the wheel.
  2.  
  3. Matchmark the both torsion bar adjustment bolt positions.
  4.  
  5. Using tool J-36202, increase the tension on the adjusting arm.
  6.  
  7. Remove the adjustment bolt and retaining plate.
  8.  
  9. Move the tool aside.
  10.  
  11. Slide the torsion bars forward.
  12.  
  13. Remove the adjusting arm.
  14.  
  15. If equipped, remove the splash shield from the knuckle.
  16.  
  17. Remove the hub nut and washer. Insert a long drift or dowel through the vanes in the brake rotor to hold the rotor in place.
  18.  
  19. Using a puller, force the outer end of the axle shaft out of the hub. Remove the shaft.
  20.  
  21. Remove the brake caliper and wire it out of the way. Remove the rotor.
  22.  
  23. Disconnect the shock absorber from control arm and compress the shock absorber.
  24.  
  25. Disconnect the inner tie rod end from the relay rod.
  26.  
  27. Support the lower control arm with a floor jack.
  28.  
  29. If necessary, disconnect the stabilizer bar from the control arm.
  30.  
  31. Remove the cotter pin from the lower ball stud and loosen the nut.
  32.  
  33. Loosen the lower ball stud in the steering knuckle using a ball joint stud removal tool. When the stud is loose, remove the nut from the stud.
  34.  
  35. Remove the control arm-to-frame bracket bolts, nuts and washers.
  36.  
  37. Remove the lower control arm and torsion bar as a unit.
  38.  
  39. Separate the control arm and torsion bar.
  40.  
  41. On 15 and 25 Series, the bushings are not replaceable. If they are damaged, the control arm will have to be replaced. On 35 Series, proceed as follows:
    1. FRONT BUSHING: Unbend the crimps with a punch. Force out the bushings with tools J-36618-2, J-9519-23, J-36618-4 and 36618-1.
    2.  
    3. REAR BUSHING: Force out the bushings with tools J-36618-5, J-9519-23, J-36618-3 and J-36618-2. There are no crimps.
    4.  

  42.  

To install:
  1. Installation is the reverse of removal but please note the following important steps.
  2.  
  3. On 35 Series, install a new front bushings, then a new rear bushing using the removal tools.
  4.  
  5. Raise the control arm assembly into position. Insert the front leg of the control arm into the crossmember first, then the rear leg into the frame bracket.
  6.  
  7. Install the bolts, front one first. The bolts must be installed with the front bolt head heads towards the front of the truck and the rear bolt head towards the rear of the truck!
  8.  

Do not tighten the bolts yet. The bolts must be torqued with the truck at its proper ride height.

  1. Start the ball joint into the knuckle and tighten the nut to specification.
  2.  
  3. Install the adjuster arm.
  4.  
  5. Using tool J-36202, increase tension on both torsion bars.
  6.  
  7. Install the adjustment retainer plate and bolt on both torsion bars.
  8.  
  9. Set the adjustment bolt to the marked position.
  10.  
  11. Release the tension on the torsion bar until the load is taken up by the adjustment bolt.
  12.  
  13. Install the wheel.
  14.  
  15. Lower the truck. Once the weight of the truck is on the wheels perform the Z height adjustment procedure in this section.
  16.  
  17. When the adjustment is correct, tighten the control arm pivot nuts to 135 ft. lbs. (185 Nm) on 1988-90 models; 140 ft. lbs. (190 Nm) on 1991-95 models and 121 ft. lbs. (165 Nm) on 1996-98 models. If the adjustment is not correct, tighten the pivot bolts to specification and have the alignment checked.
  18.  



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Fig. Fig. 3: Installing the lower control arm-K-Series

 
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