GM Full Size Vans 1967-1986 Repair Guide

Shock Absorbers



The usual procedure for testing shock absorbers is to stand on the bumper at the end nearest the shock being tested and start the vehicle bouncing up and down. Step off; the vehicle should come to rest within one bounce cycle. The stiffness of the suspension on some models makes this rather difficult, unless you are a very "substantial'' individual. Another good test is to drive the vehicle over a bumpy road. Bouncing over bumps is normal, but the shock absorbers should stop the bouncing after the bump is passed, within one or two cycles.


See Figure 1

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Fig. Fig. 1: Remove the upper bolt and nut from the shock absorber

The usual procedure is to replace shock absorbers in axle pairs, to provide equal damping. Heavy duty replacements are available for firmer control.

  1. Raise and support the front end as necessary.
  3. Remove the bolt and nut from the lower shock end.
  5. Remove the upper bolt and nut.
  7. Purge the new shock of air by extending it in its normal position and compressing it while inverted. Do this several times. It is normal for there to be more resistance to extension than to compression.
  9. Install the shock absorber. Tighten the shock bolts to 75 ft. lbs. (101 Nm) except for the 1967-70 lower bolt; tighten these to 55 ft. lbs. (74 Nm).