On a rough, winding road the driver of a car with worn shocks is in danger of losing control. Weak shocks or struts permit excessive rebound of the wheels, allowing them to become airborne. During this brief period the tire is in the air, it loses contact with the road surface. All steering and braking is lost

Rear end sags due to overload affects steering and handling. This condition also can increase wear of tires, suspension parts, and steering linkage and drive line components.
Air shocks, along with good springs, help prevent rear end sag

Tips

Shocks and struts are part of the complex steering/suspension system of the vehicle. Everything within system must conform to specifications for satisfactory ride control and safety.
Have wheel alignment and balance checked periodically; inspect and rotate tires every 6,000 miles or twice a year.
If your vehicle has more than 25,000 miles on the original shock absorbers or struts, internal parts may be worn. From that point throughout their service life they also should be inspected at every 6,000 miles or twice a year

Shock absorbers cannot be repaired. When they fail they must be replaced. For superior performance and long life, invest in the best shocks or struts available able for your particular needs. The Ride Control Institute recommends gas filled shocks or struts which provide quick reaction to various road conditions, improve handling and reduce sway.
For best control and handling of your vehicle, replace shocks or struts in pairs of in sets of four.
Periodically your car should have a thorough inspection by a qualified technician
Warning Signs

Signs You May Need New Shocks or Struts:
• Roll or sway on turns.
• Front end dives when braking.
• Rear end "Squats" when accelerating.
• Vehicle bounces or slides sideways on a winding, rough road.
• Vehicle "bottoms out" (with a thump

Preventive Checkups
Shock absorbers and struts seldom go bad all at once. Instead they gradually lose their ability to control the vehicle's stability. You may be unaware of deteriorating ride control until the condition has become serious. For this reason it's wise to test and inspect shocks and struts regularly

Things to look for:
• Leaks on hosing
• Dents on the strut or shock body
• Worn rubber mounting bushings
• Abnormally worn or cupped tire tread
• Damaged or missing compression bumpers
Damaged or missing protective boots
Pitted or dented piston rod

Purpose of Shocks & Struts
In the true sense of the word, a shock absorber is not a shock absorber. It's the springs, not the shock absorbers that absorb road shocks. If a spring had to do this without the dampening, or controlling effects of a shock absorber, it would continue to bind after hitting the bump. And, since the springs support the weight of the body, the entire vehicle would continue to bounce after a bump, creating an unstable and uncomfortable condition

While dampening of spring action still is their main purpose, shock absorbers (and, on most late model cars, "struts") also play a vital role in of controlling a vehicle's handling and ride