When you drive over a speed bump, does your car feel like a bucking bronco? Or is every jaunt a bumpy ride no matter how smooth the road is? Then it’s probably time to take a look at your car’s suspension system and consider replacing the shocks and struts.
What Are Shocks and Struts?
Every car and truck is suspended by a combination of springs, shocks, and struts. If you look behind any of your four wheels, you’ll see these hard-working parts moving up and down, up to 1,900 times per mile.
By the time you’ve driven your vehicle 50,000 miles, your shock and struts will have done their job 75 million times, working together with your brakes, steering, suspension, tires, and advanced crash avoidance systems to keep you in control and safe on the road.
What Do Shocks and Struts Do?
Shock and struts in good condition will help your car handle bumps, rocks, sudden stops, skids, potholes, gusts of wind, or sharp turns. You control the shifts in weight from side to side, front to back, and top to bottom to keep your tires in contact with the road and you maintain control of your vehicle.
- Maintain your tire’s contact with the road.
- Prevent your tires and wheels from moving up and down too much.
- Contribute to stability as you accelerate, stop and turn.
- Increase driving comfort by absorbing shock and bumps from irregular road surfaces.
- Help control a vehicle’s body movement (side-to-side roll, hop).
- Promote even wear for longer tire life.
Contrary to popular belief, shock and struts do not typically support the weight of your vehicle or any loads that your truck or vehicle might support. The springs do this job. Worn shocks and struts, however, put more stress on the springs and other critical suspension parts.
Without the control that a good shock absorber or strut provides, these other parts will become overloaded, leading to fatigue and premature wear.
How do Shocks and Struts work?
Shock absorbers and struts help stabilize your vehicle’s movements and improve control when turning, braking, accelerating or on rough road surfaces. Today’s vehicles use shock absorbers, struts, or a combination of both.
The fundamental difference is that a damper is a separate component, while the strut combines the damper and other features into a single assembly. Both help stabilizes the vehicle and keeps the tires in contact with the road. Without shock absorbers, your vehicle would bounce down the road.
How long can you expect your shock absorbers or struts to last? That depends. Driving on rough or unpaved roads, towing a trailer, or carrying heavy loads can shorten their lifespan. If used heavily, you might try replacing them after 40,000 or 50,000 miles or sooner. Under normal conditions, 75,000 to 90,000 miles might be reasonable.
What is the difference between shocks and struts?
Shock and struts are often referred to interchangeably, but there are some major differences between them. If your vehicle requires struts, you cannot replace shock absorbers (and vice versa).
Shock absorbers are individual suspension components that help coil springs absorb road impact. Without shocks, the vehicle would spin out of control! They help keep the tires in contact with the road instead of springing up after a bump.
A strut combines the shock absorber and coil spring components into a single unit. Struts not only absorb bumps and shock but also provide structural support. They replace the upper control arm and upper ball joint required on traditional suspension systems.
Does my vehicle have shocks or struts?
Every wheel has either a strut or a shock. They come in pairs; If you have a shock on the left rear wheel, you also have a shock on the right rear wheel. However, your vehicle may have shock absorbers on one axle and struts on the other axle.
In fact, most modern vehicles have struts on the front axle and shock on the rear axle. They may have struts on both axles, but it’s rare to have only shock absorbers.
There are 3 easy ways to find out if your vehicle has shock absorbers or struts.
- Consult your user manual. The owner’s manual should contain information about the suspension setup for your specific model.
- Look under the car. As long as you know what you’re looking for, you should be able to see if your vehicle has shock absorbers or struts associated with each wheel.
- Ask a technician. Ask your technician for the next vehicle service! You can identify what component(s) your vehicle has and – bonus! – They can also let you know if the shock absorbers/struts will need to be replaced soon.
The Warning Signs of Worn Shocks and Struts
While many variables go into the lifespan of your shock absorber or strut (hello, potholes), experiencing any of these seven symptoms means it’s time for a replacement.
- Instability at highway speeds. Your vehicle never feels completely stable on the freeway and is constantly moving up and down. The movement may be slight, but you notice it.
- The vehicle alternately “tilts” sideways. When taking a sharp turn or exit, your vehicle will lean or “tilt” to the outside of the turn and feel wobbly.
- The front dives more than expected under heavy braking. You may not realize this until you have to slam on the brakes hard.
- Rear-end squat during acceleration. You will notice that the front end of your vehicle rises while the rear “squats” under hard acceleration.
- Tires bouncing excessively. After hitting a bump, you may feel a tire (or tires) react or “bounce” for a period of time. You may also hear a rattling noise.
- Unusual tire wear. Because the tire is not held firmly to the road, the tread wears in waves rather than evenly.
- Leaking liquid on the outside of shock absorbers or struts. This is a sign that the seals have broken and are leaking the internal fluids necessary for proper operation.
What Will Happen If I Drive on Worn or Damaged Shocks and Struts
Staying in contact with the road is important, especially when going over bumps or keeping up with highway traffic. Your vehicle’s suspension system, including shock absorbers and/or struts, is excellent for this task if every part is working properly.
Over time, these parts wear out. You might not even notice it as it gradually breaks down. If they are not working properly, it can affect your control and safety. It can also cause additional wear and tear on other parts of your vehicle, including your tires.
Replacing worn parts before they go bad can help keep your vehicle’s electronic systems and suspension working properly, extend the life of your vehicle – and keep you safer on the road.
Shocks and Struts Aren’t Just About a Smooth Ride
Today’s vehicles have sophisticated electronic safety systems (vehicle stability systems, ABS (anti-lock brakes), traction control, collision prevention control and automatic braking). These all work together to keep the tires in proper contact with the road and provide the greatest possible stability.
If you make an unexpected hard stop or swerve, your vehicle’s crash avoidance systems will immediately send electronic signals to the brakes and other key components. When ride control parts such as shock and struts are worn, they may not respond properly.
In addition, the braking distance could increase and brakes and tires wear out faster. In addition, the springs could be additionally loaded.
How Long Do Shocks/Struts Last?
This depends on many factors. You can think of shock absorbers or struts like tennis shoes. If you only wear them on the weekends to go to the mall, they will last a lot longer than someone who wears them every day, skateboards, and uses their shoes as brakes quite often!
This means your shocks or struts will last longer if you drive fewer miles, drive on nice smooth roads, don’t drive like speed racers and don’t carry a lot of weight in your vehicle.
On average, if your car has been babysat, you can expect your shock absorbers/struts to last around 10 years. If you’ve really used your car as a workhorse, 5 years is probably all you can expect. This means that for the average rider, 7 or 8 years is the maximum life expectancy of most shock absorbers and struts.