How Your Car's Suspension System Works: Springs, Shocks, and Struts Explained
Your suspension system does much more than smooth out bumps — it maintains tire contact with the road, controls body motion during cornering and braking, and directly affects every aspect of your vehicle's handling. Here's how it all works together.
The Two Jobs of Your Suspension
Vehicle suspension serves two primary functions: supporting the vehicle's weight (sprung mass) above the wheels, and allowing the wheels to move independently over road irregularities without transmitting harsh impacts to the occupants. The key is that tires must stay in contact with the road to generate braking, cornering, and acceleration forces.
Springs: Supporting the Vehicle's Weight
Springs absorb the initial shock of road impacts by compressing and extending. Coil springs (most common on modern vehicles), leaf springs (common on trucks and SUVs), and torsion bars all store and release energy. Springs alone would create a bouncing, uncontrolled ride — which is why dampers are essential.
Shock Absorbers: Controlling Spring Oscillation
Shock absorbers (shocks) convert spring energy into heat through fluid displacement inside the shock body. A piston moves through hydraulic fluid; the resistance controls how quickly the spring compresses and rebounds. Without shocks, your vehicle would bounce for several seconds after every bump.
Struts: The Spring and Shock in One Unit
A strut combines the spring and shock absorber into a single structural assembly that also serves as part of the steering knuckle. Struts are a structural component — they bear vehicle weight and steering loads in addition to their suspension duties. Replacing struts is more involved than replacing standalone shocks.
| Component | Function | Typical Replacement |
|---|---|---|
| Coil spring | Supports weight, absorbs initial impact | Only if broken or collapsed |
| Shock absorber | Controls spring movement, improves stability | 50,000–100,000 miles |
| Strut assembly | Structural + suspension + steering | 60,000–100,000 miles |
| Control arm | Links suspension to frame, allows wheel movement | 80,000–150,000 miles |
| Sway bar link | Reduces body roll in corners | 50,000–100,000 miles |
When replacing shocks or struts, always replace in axle pairs. Mismatched damping on the same axle creates handling imbalances and unpredictable behavior.
Ready to Schedule Service in Newbury Park?
CAL Tire and Auto Repair is here to help. Our ASE-certified technicians serve drivers across Newbury Park, Thousand Oaks, Westlake Village, Camarillo, Agoura Hills, and Simi Valley. Visit us at 1180 Newbury Rd or call to speak with a service advisor.
Frequently Asked Questions
How do I know if my shocks or struts are worn?
Common signs include excessive body bounce after bumps, nose-diving under braking, leaning heavily in corners, uneven tire wear, and a general sense of floating or instability. Our free inspection can confirm worn components.
Does suspension wear affect my brakes?
Yes — worn shocks and struts increase stopping distances by allowing wheel hop during hard braking. A study by the European Brake Association found that vehicles with worn shocks required up to 22% more stopping distance in emergency stops.
What is a wheel alignment and how does it relate to suspension?
Wheel alignment refers to the angles of the wheels relative to each other and the road. Suspension wear — especially in bushings and ball joints — causes alignment to drift, leading to uneven tire wear and pulling. Always check alignment when replacing suspension components.