Suspension coil spring

Between suspension arms or struts and the body.

The spring stores energy as the wheel moves; the damper controls the resulting oscillation.

A weight-bearing cushion that compresses over bumps.

Uneven ride height, broken coils or changed handling require inspection.

Wear is condition-based and strongly affected by roads, loads, impacts and seals. There is no universal replacement mileage.

Links and bushings are smaller repairs than complete adaptive struts or air-spring systems; alignment may be needed after work.

BMW passenger cars and SAVs; spring, damper and axle design depend on chassis and options.