Struts serve multiple purposes because different components are integrated into one assembly. While the vehicle is moving, its spring supports the vehicle’s weight to allow it to adapt to road irregularities. Also while traveling, the internal shock absorber dampens the spring movement as it rebounds and compresses. Struts affect vehicle control (steering, braking and wheel alignment) and riding comfort by providing structural support to the suspension, according to monroe.com.
Signs of worn struts will give you an indication that they need service or replacing; these signs include excessive bouncing, bottoming out, cupping wear on the tires, rocking back and forth and nose-diving or drifting while breaking. Generally, as a rule the coil springs replaced at the same time that the struts are changed or replaced.
A qualified service technician should inspect and check your vehicle’s suspension system on a regular basis. The struts should be checked at least once a year usually at the same time the wheels are aligned. Wear on the strut carriage is gradual and incremental losses are not noticeably apparent in handling and control. A yearly inspection of the vehicle may catch problems before they become severe enough to require the costly replacement of the struts.