GM S-Series Pick-ups and SUV's 1994-1999 Repair Guide

Shock Absorbers

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REMOVAL & INSTALLATION



2WD Vehicles

See Figure 1

  1. Raise and support the front of the vehicle safely using jackstands.
  2.  
  3. Using an open end wrench, hold the shock absorber upper stem to prevent it from turning, then remove the upper stem retaining nut, the retainer and rubber grommet.
  4.  



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Fig. Fig. 1: Common front shock absorber mounting-2WD vehicles

  1. Remove the shock absorber-to-lower control arm retaining bolts and lower the shock absorber assembly from the bottom of the control arm.
  2.  
  3. Inspect and test the shock absorber; replace it, if necessary.
  4.  

To install:
  1. Fully extend the shock absorber stem, then push it up through the lower control arm and spring so that the upper stem passes through the mounting hole in the upper control arm frame bracket.
  2.  
  3. Install the upper shock absorber nut and tighten to 100 inch. lbs. (11 Nm) on 1994 models 145 inch lbs. (16 Nm) on 1995 models, 54 ft. lbs. (73 Nm) on 1996 models, or 106 inch lbs. (12 Nm) on 1997-99 models while holding the stem with an open end wrench. Be careful not to crush the rubber bushing.
  4.  
  5. Install the shock absorber-to-lower control arm retaining bolts and tighten to 20 ft. lbs. (27 Nm) on 1994-95 models and 54 ft. lbs. (73 Nm) on 1996 models, or 22 ft. lbs. (30 Nm) on 1997-99 models.
  6.  
  7. Remove the jackstands and carefully lower the vehicle.
  8.  

4WD Vehicles

See Figures 2 and 3

  1. Raise and support the front of the vehicle safely using jackstands.
  2.  
  3. Remove the tire and wheel assembly to ease access.
  4.  
  5. Remove the shock absorber-to-lower control arm nut and bolt (using a backup wrench), then collapse the shock absorber.
  6.  



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Fig. Fig. 2: Loosen and remove the shock absorber lower mounting bolt



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Fig. Fig. 3: Then loosen the upper mounting bolt and remove the shock from the vehicle

  1. Remove the upper shock absorber-to-frame nut and bolt (again, using a backup wrench).
  2.  
  3. Inspect and test the shock absorber; replace it, if necessary.
  4.  

To install:
  1. Position the shock absorber to the mounting brackets.
  2.  
  3. Install the upper and lower retaining bolts (inserted from the front of the vehicle).
  4.  
  5. Install the retaining nuts to the bolts, then tighten the retainers to 54 ft. lbs. (73 Nm).
  6.  
  7. Install the tire and wheel assembly, then remove the jackstands and carefully lower the vehicle.
  8.  

TESTING



See Figure 4

The purpose of the shock absorber is simply to limit the motion of the spring during compression and rebound cycles. If the vehicle is not equipped with these motion dampers, the up and down motion would multiply until the vehicle was alternately trying to leap off the ground and to pound itself into the pavement. Contrary to popular rumor, the shocks do not affect the ride height of the vehicle. This is controlled by other suspension components such as springs and tires. Worn shock absorbers can affect handling; if the front of the vehicle is rising or falling excessively, the "footprint" of the tires changes on the pavement and steering is affected. The simplest test of the shock absorber is simply push down on one corner of the unladen vehicle and release it. Observe the motion of the body as it is released. In most cases, it will come up beyond it original rest position, dip back below it and settle quickly to rest. This shows that the damper is controlling the spring action. Any tendency to excessive pitch (up-and-down) motion or failure to return to rest within 2-3 cycles is a sign of poor function within the shock absorber. Oil-filled shocks may have a light film of oil around the seal, resulting from normal breathing and air exchange. This should NOT be taken as a sign of failure, but any sign of thick or running oil definitely indicates failure. Gas filled shocks may also show some film at the shaft; if the gas has leaked out, the shock will have almost no resistance to motion.

Click image to see an enlarged view

Fig. Fig. 4: When fluid is seeping out of the shock absorber, it's time to replace it

While each shock absorber can be replaced individually, it is recommended that they be changed as a pair (both front or both rear) to maintain equal response on both sides of the vehicle. Chances are quite good that if one has failed, its mate is weak also.

 
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