GM Service Manual Online
For 1990-2009 cars only

Front Caster and Camber Adjustment Rear Wheel Drive

    Important: Before adjusting the caster and the camber angles, the front bumper should be jounced three times to allow the vehicle to return to the normal height. Refer to Trim Height in Suspension General Diagnosis.

  1. The caster and the camber adjustments are made by inserting shims between the upper control arm shaft and the frame bracket. The shims may be added, subtracted, or transferred in order to change the readings.

  2. Object Number: 82  Size: SH
  3. In order to adjust the caster and the camber, loosen the upper control arm shaft to frame nuts (1). Add or subtract the shims (2) as required. Torque the nuts. Check the toe-in after changing the caster or the camber.
  4. Adjust the caster by transferring the front shims to the rear, or the rear shims to the front.
  5. The transfer of the one shim from the rear bolt to the front bolt will decrease the positive caster.

  6. Adjust the camber by changing the shims at both the front and the rear of the shaft.
  7. Adding an equal number of shims at both the front and rear of the cross shaft will decrease positive camber.

  8. A normal shim pack will leave at least two and one-half threads of the bolt exposed beyond the nut. The maximum shim pack cannot be thicker than 19.5 mm (0.77 in). The difference between the front shim packs and the rear shim packs must not exceed 10 mm (0.40 in). If these requirements cannot be met, check for damaged control arms and damaged related parts.
  9. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  10. Tighten the nut on the thinner shim pack first.
  11. Tighten
    Tighten the nuts to 110 N·m (81 lb ft)

    Tightening the nut on the thinner shim pack first improves the shaft to frame clamping force and torque retention.

Front Caster and Camber Adjustment Full-Time Four-Wheel Drive

Removal Procedure

    Important: Before adjusting the camber and the caster, remove the knockout from each frame bracket connecting the upper control arm to the vehicle.

  1. Raise the vehicle. Support the vehicle with safety stands.
  2. Support the lower control arms with a jack or with safety stands.
  3. Important: The jack or the stand must remain under the lower control arm torsion bar seat during the removal and the installation procedure in order to retain the lower control arm position.

  4. Remove the tire and the wheel assembly. Refer to Wheel Removal in Tires and Wheels.

  5. Object Number: 163494  Size: SH
  6. Remove the following components from the upper control arm:
  7. • The upper control arm nuts (2)
    • The upper control arm bolts (6)
    • The adjusting cams (1)
    • Note the position of the adjusting cams (lobes down) and the adjusting cam bolts before removal.
  8. Reposition the upper control arm (4) in order to access the frame brackets (5).
  9. Remove the frame bracket knockout (if necessary). Refer to Frame Bracket Knock Out Removal .
  10. Repeat the procedure on the other upper control arm frame bracket.

Installation Procedure


    Object Number: 163494  Size: SH
  1. Install the upper control arm (4) to the frame brackets (5).
  2. Install the adjusting cams (1) with the lobes down.
  3. Install the adjusting cam bolts (6).
  4. Install the nuts (2).
  5. Hand tighten the nuts.

  6. Install the tire assembly and the wheel assembly. Wheel Installation in Tires and Wheels.
  7. Repeat the procedure on opposite control arm assembly.

    Proceed to align the vehicle.

  8. Make the caster and the camber adjustments by rotating the offset cam bolt (6) and the cam (1) in the slotted frame bracket (5) in order to reposition the control arm (4).
  9. In order to adjust the caster and the camber, loosen the upper control arm to frame attaching bolts.
  10. Rotate the cam (1) by rotating the bolt head (6).
  11. In order to adjust the camber, use the following procedure:
  12. 9.1. Hold the cam bolt (6) and loosen the nut (2).
    9.2. Turn the cam bolt in order to obtain change equal to one half of the needed correction.
    9.3. Hold the cam bolt (6) in this position in order to maintain the setting.
    9.4. Obtain the remaining one half of the needed correction by repeating steps 1 through 3 to the other cam bolt (7).
    9.5. Turn the cam lobe in the same direction.
    9.6. When this camber adjustment is followed, the caster setting will not be affected.
  13. In order to adjust the caster, use the following procedure:
  14. 10.1. Note the camber reading.
    10.2. Hold the front cam bolt (6) and loosen the nut (2).
    10.3. Turn the front cam bolt in order to obtain a change equal to ¼ of the desired caster change.

    At the front cam bolt, a positive camber change produces a positive caster change and a negative camber change produces a negative caster change.

    10.4. Hold the cam bolt (6) in this position while tightening the nut (2) in order to maintain setting.
    10.5. Hold the rear cam bolt (6) and loosen the nut (2).
    10.6. In order to return the camber to the setting that you noted earlier, turn the cam bolt (6) by turning the cam (1) lobe in the opposite direction.
    10.7. Check the caster setting.

    Repeat the above procedure if not within specifications.

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

    10.8. When adjustments are complete, hold the cam bolt (6) head in order to ensure the cam position does not change while tightening the nut.

    Tighten
    Tighten the nut to 110 N·m (81 lb ft).