Strut and shock replacement intervals are a little more subjective than just a glance at the odometer. Struts and shocks should be replaced based on their performance more than the miles. Most shocks or struts will last 30,000 to 90,000 miles depending on driving habits and the condition of the roads you drive on. That’s a pretty wide range to depend on mileage alone.

A shock absorber’s only function is to stabilize the vehicle any time it is disturbed such as bumps, stopping, or cornering. If you feel a bit of a bounce after hitting a bump or if the car nosedives when braking or sways too much going around corners, your shocks may need to be replaced.

Your car’s struts perform the same function as the shocks, plus they act as an integral part of the suspension. A strut replaces the upper control arm and ball joint that a conventional independent suspension would have. This means that in addition to the symptoms that would indicate a bad shock, we need to add the possibility of misalignment, noise over bumps, and noise while turning.

Both shocks and struts are filled with oil, which is used to dampen the movement of the suspension. One good indicator that the shock or strut is on it’s way out is leaking fluid. A leaking shock or strut will quickly run out of oil and lose its damping ability.

Bad shocks and struts have been shown to increase stopping distances, decreased cornering control, increased tire wear and increased wear on other suspension components. Even with all of those potential problems, the biggest reason to replace your shocks or struts is the ride feel. Most of the good feelings of being in control and having a car that just feels like it’s put together nicely is a result of having good shocks and struts.
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