What Shocks and Struts Do
Shocks and struts are part of your vehicle’s suspension system. They absorb the impact your car experiences, especially when it goes over bumps and potholes. Shocks and struts make your trip fairly smooth but without them, you feel every bump in the road and the car may rock or wobble.
While both terms are used interchangeably, a strut is simply the shock absorber unit with the corner spring. Attached to the body or frame and the control arms, the shock absorber is a piston holding hydraulic fluid, which flows through the car’s restrictive valves and channels, creating resistance against the spring’s natural movement.
Compared to the spring, the shock absorber moves at a significantly slower pace. This feeling gets transferred through the rest of the vehicle’s frame and helps create a more stable center of gravity, which helps the tires stay on the pavement and gives the driver better control the car.
Traditionally, cars have four struts – one on each wheel, or two in the front and two in the rear. Compared to the rest of your car’s parts, they need significantly less maintenance – but that doesn’t mean they don’t experience damage.
Typically, these parts last from four to 10 years, depending on the degree of wear and tear. Many car manufacturers recommend replacing the struts and shock absorbers every 40,000 to 50,000 miles. However, under normal driving conditions with a more modern vehicle, these parts may last longer.
Signs of Damage
Generally, it’s time to replace a shock absorber when:
- You notice leaking. Without hydraulic fluid, the shock absorber and strut will stop working. Even if the leak isn’t clear, a wet film right outside of the part indicates oil has started coming out.
- You’ve hit a major pothole or the curb, which bends the strut or causes alignment issues. Without replacement, this imbalance places extra strain on the remaining shock absorbers.
- Your car bounces more than usual, especially when you go over railroad tracks or around curves.
- It takes longer to brake or you feel a sharp sensation through the steering wheel when you apply the brakes.
- You see uneven tire wear, including worn bushings, which cause vibrations to go through the tire and accelerate its wear. Your tires may also display “cupping” – evenly spaced tread wear.
- The vehicle “pitches” more as you accelerate or brake, dipping in front or dropping in back.
- Your tires and wheels seem to “hop”, even on smooth roads.
- Shock housing displays denting, often caused by rocks or other road debris. Damage may affect the piston’s movement or cause the shock absorber to leak.
- You hear a knocking noise whenever you go over bumps.
Before your car needs a replacement, several factors can damage or place a great degree of wear on your car’s struts:
- Regularly driving over rough roads – pavement with deep potholes, large cracks and sharp ridges or unpaved roads.
- Regularly carrying or transporting heavy loads, especially over long stretches of unpaved roads.
- Driving at high speeds over damaged pavement.
- Your car has been through a harsh winter, potentially with salt contributing to corrosion.
In all these scenarios, worn-out, leaking valves don’t create the resistance the car needs, causing you to feel everything as you drive. You could more easily lose control and place a greater degree of wear on the rest of your car.
Repairing Shock Absorbers & Struts
If you notice any combination of the signs outlined above:
- Make an appointment to have your car’s full suspension system inspected for wear, damage and leaks. In certain cases, shock absorber damage could be tied to ball joint, control arm or tie rod issues.
- Consider a “bounce test”, in which each corner of the vehicle is pushed down and released. Weak struts will bounce up and down more.
- Consider strut replacement. For even wear, struts are replaced in pairs – front or the back.
- The sway bar – also called a stabilizer bar – may need to be replaced, in addition to the strut. As the older, damaged strut is removed, this part is also taken out and may show some damage or seize up during replacement.
Concerned about your car’s shock absorbers and struts? Whether your car’s suspension system needs maintenance or new parts, make an appointment with our Naugatuck shop.