Low pressure gas shocks are charged with Nitrogen gas, and it is important not to open, puncture, or apply heat to them. Before installing a new shock absorber, hold it upright and extend it fully, then invert it and fully compress and extend it at least three times to bleed trapped air. Begin by raising the vehicle for better access and removing the bolt and nut that attach the shock absorber to the lower bracket on the 
Radius Arm. Next, take off the nut, washer, and insulator from the shock absorber at the frame bracket and remove the shock absorber. Position the washer and insulator on the shock absorber rod, then place the shock absorber to the frame bracket and loosely install the attaching nut. After that, position the shock absorber to the lower bracket and loosely install the attaching bolt and nut. Finally, tighten the lower attaching bolts to 40-63 ft. lbs. and the upper attaching bolts to 25-35 ft. lbs. The shock absorber's purpose is to limit the motion of the spring during compression and rebound cycles; without them, the vehicle would experience excessive up and down motion. Contrary to popular belief, shocks do not affect ride height, which is determined by other suspension components. Worn shock absorbers can impact handling, and if the front of the vehicle rises or falls excessively, it alters the tire footprint on the pavement, affecting steering. A simple test involves pushing down on one corner of the unladen vehicle and observing the motion as it is released; it should come up beyond its original rest position, dip back below it, and settle quickly. Any excessive pitch motion or failure to return to rest within 2-3 cycles indicates poor function. Oil-filled shocks may have a light film of oil around the seal due to normal breathing, which is not a sign of failure, but thick or running oil indicates a problem. Gas-filled shocks may also show some film at the shaft, and if gas has leaked out, the shock will have little resistance to motion. While individual shock absorbers can be replaced, it is advisable to change them as a pair to ensure equal response on both sides of the vehicle, as a failed shock often indicates that its counterpart is also weak.