Springs do most of the work of the suspension system.  The most common types of springs are coil and leaf, but air springs and torsion bars are becoming more common. The body of the vehicle is “suspended” by the springs.

Some vehicles have struts in their suspension system. Struts are a compact combination of springs and shocks. They do the same job but in a single package.

Shocks wear out gradually, so it can be difficult to notice when they need to be replaced. There’s no definitive point when a vehicle’s ride goes from smooth and controlled to a bit imprecise. To check if your shocks or struts are worn, you should first visually inspect them. If they are leaking fluid, they need to be replaced.

Replacing struts can put a vehicle out of alignment, so an alignment check should always follow this type of repair.