Shocks are not replaced as often as they should be because wear is not easy to measure. It’s not like a brake pad or brake rotor where the thickness can be measured to determine if the part is worn out. It’s more subjective with shocks. The gradual loss in ride control over time often passes unnoticed and is considered more of a ride comfort issue than a safety issue by many motorists. Yet tests have shown that weak shocks reduce handling stability, braking distances and overall driving safety.
Another obstacle that hinders the sale of replacement shocks is the high cost of some of today’s sophisticated electronic dampers (the magnetic type as well as the adjustable variety). Some of these units can cost hundreds of dollars, and may only be available from a new car dealer. On some vehicles, electronic shocks can be replaced with less expensive conventional shocks, or in the case of original equipment air shocks, converted to standard shocks if the original dampers or air compressor have called it quits. These conversion kits are very popular for older luxury cars such as Buicks, Cadillacs and Lincolns with aging air ride suspensions that have gone flat.
Maintaining good ride control across a broad range of driving conditions is important because not only does it improve ride quality but also handling stability and driving safety. By dampening the movements of the suspension, shocks and struts keep the tires in contact with the road surface. This prevents the tires from bouncing and skipping with every bump and dip in the road. Tires that do not stay in contact with the road can’t provide good traction, steering stability or braking friction. Too much tire bounce may even trigger the ABS system unnecessarily when braking.
The issue of vehicle stability is especially critical with SUVs because of their higher center of gravity. When making sudden steering maneuvers or turning sharply, the body experiences a lot more roll than a typical passenger car. Although most newer SUVs are now equipped with stability control, if the shocks can’t keep the body under control, it may increase the potential for a rollover.
Another reason for replacing shocks (even brand new ones) is to upgrade handling performance. Most shocks and struts today are pressurized with nitrogen gas to minimize foaming and shock fade. This also provides a firmer, more stable ride. In a twin-tube shock, 100 to 150 psi is typically used though some performance twin-tube shocks may contain as much as 250 psi inside.
With monotube shocks and struts, a floating piston separates the gas from the oil. Because of the larger surface area, a much higher gas charge is normally used: typically 360 to 400 psi.
Replacing the original equipment shocks or struts with high-performance aftermarket shocks/struts can improve handing agility. Adjustable dampers are even better because they allow the vehicle owner to dial in the desired firmness they want for changing driving conditions.
