That depends. “Driving on rough or unpaved roads, towing a trailer or carrying heavy loads, can shorten their functional life,” says Reina. “With heavy use, you could be looking to replace them at 40,000 or 50,000 miles or sooner. Under normal conditions, 75,000 to 90,000 miles might be reasonable.”

Do rusted shocks need to be replaced?

Struts don't need to be replaced unless your vehicle is bouncing like it's on a pogo stick or bottoms out in potholes and over railroad tracks — or unless a mechanic finds that they're leaking fluid or have been damaged. In some climates, they can also rust.

Are rusty shocks a problem?

Surface rust is a normal atmospheric occurrence. It will have little effect on the performance of the shocks or calipers. Only when it gets to a severe condition - which can take many years - should these parts be replaced due to rust.