The purpose of the shock absorber is simply to limit the motion of the spring during compression (bump) and rebound cycles. If the vehicle were not equipped with these motion dampers, the up and down motion of the vehicle 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 nor do they affect the ride quality except for limiting the pitch or bounce of the vehicle. These factors are 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 response is affected. The simplest test of the shock absorbers is simply to 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 its original rest position, dip back below it and settle quickly to rest. This shows that the damper is slowing and 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.
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.
REMOVAL & INSTALLATION
- Remove the hubcap and loosen the lug nuts.
- Raise the front of the truck and support it with safety stands.
- Remove the wheel.
- Unfasten the double nuts at the top end of the shock absorber. Remove the cushions and cushion retainers.
- Remove the lower through-bolt.
- Remove the shock absorber.
Install the shock absorber and tighten the lower mounting nuts/bolt to the appropriate torque:
T100 and Tacoma-101 ft. lbs. (137 Nm)
- Tighten the upper mounting nut to 18 ft. lbs. (25 Nm).
- Install the wheels and lower the truck.
Once removed, the shock should be carefully inspected for any signs of leakage. 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.
Hold the shock firmly in each hand and compress it; compression should be reasonably even and smooth. Release the piston end; it should return smoothly and at an even pace. Stretch the shock, checking again for smooth motion and any abnormal resistance.
DISPOSAL OF GAS-FILLED SHOCK ABSORBERS
The factory installed gas shocks found on some vehicles contain nitrogen. The gas is under pressure, even with the shock removed from the vehicle. To eliminate the possibility of explosion after disposal, the shock case must be drilled to release the gas.
Drill a 0.079-0.118 in. (2-3mm) hole at a point 1.18 in. (30mm) above the base of the shock case. Drill a second hole 1.97 in. (50mm) below the edge of the piston cover (with the shock compressed).