Struts or Shock Absorbers Bench Test (Non Spiral Groove)

TESTING PROCEDURE
It is not necessary to purge air from non-spiral groove shock absorbers. These shock absorbers contain a gas-filled cell within the absorbers reservoir. These shocks differ from spiral groove shock absorbers. Spiral groove shocks contain an air-filled cell within the reservoir.

1. Remove the shock absorber from the vehicle.
^ For RWD vehicles, refer to SHOCK ABSORBER REPLACEMENT (REAR WHEEL DRIVE) in FRONT SUSPENSION.
^ For F4WD vehicles, refer to SHOCK ABSORBER REPLACEMENT (FULL-TIME FOUR-WHEEL DRIVE) in FRONT SUSPENSION.

Important: Do not clamp the vise jaws on the shock upper stem threads or the reservoir.

2. Place the shock absorber in a vise.
^ Clamp the vise jaws on the top mounting stud of the shock.
^ Hold the shock vertically in the vise with the bottom end up.
3. Pump the shock at various rates of speed. Observe the rebound force.
^ The rebound force normally is stronger than the compression force (approximately 2 to 1).
^ The rebound force should be smooth and constant for each stroke rate.
4. Compare this shock with a good shock absorber.
5. If you observe any of the following conditions, replace the shock absorber:
^ A skip, or a lag, at reversal near mid-stroke
^ A seizing (except at the extreme ends of travel)
^ A noise, a grunt or a squeal, after completing one full stroke in both directions
^ A clicking noise at fast reversal