Shocks and Struts

What are shocks and struts and where are they located?

Shock absorbers (shocks for short) and struts are parts of your car's suspension that improve the smoothness of your ride and your vehicle's handling by acting as dampers for the springs.

The springs, whether coil springs, leaf springs or torsion bars absorb the shocks of the road.  When one of your wheel hits a bump, it lifts up, compressing the spring.  Once compressed, the spring wants to expand. The shock or strut pushes the wheel back, keeping the springs under control and keeping your car on the road, preventing the suspension from bouncing when the wheel rebounds.  Automotive shocks and struts control the energy transferred from the road as you drive, to the spring.

Shocks keep springs under control.  They're filled with hydraulic fluid (oil) and many contain pressurized nitrogen gas.  A piston inside presses against the hydraulic fluid, the fluid slows it down, restricting its movement.  Gas is used in gas shocks to keep air bubbles from forming in the hydraulic fluid.  Air bubbles would allow for the piston to push through the gas.

Your vehicle may come from the factory with struts for all four wheels, shocks for all four wheels, struts in the front and shocks in the rear, or struts in the rear and shocks in the front, depending on the model. 

What is the difference between shocks and struts?

Struts are integral parts of the suspension without which you could not drive the car.   Struts usually have the spring attached.  Shocks may be attached to the spring (in what's known as a coilover shock) or separate from the spring. 

Shocks are used in solid axle suspensions where the wheel connects directly to the axle, double wishbone suspensions that use an upper and a lower control arm for each wheel, and multilink suspensions that use multiple arms to control each wheel.  Shocks usually attach to the axle housing or the lower control arm. 

Struts are used in a type of suspension called MacPherson suspension.  The strut plays a double role by acting just like a shock absorber, taking the place of the upper control arm, helping to locate the wheel and support the weight of the vehicle.  A strut attaches to the wheel spindle. 

If you remove a shock from a vehicle, provided that it's not a coilover shock and the spring stays behind then the vehicle can still drive, but the ride will be bouncy, uncomfortable and difficult to control.  Without a strut, the wheel would cave in and the vehicle would sink to the ground. 

What are the different types of shocks? 

Types of shocks include: monotube shocks, twin-tube shocks, adjustable shocks, electronic shocks, coilover shocks, and air shocks. 

Monotube shocks are the most basic type, with gas separated from the fluid by a divider. 

In twin tube shocks, the piston displaces hydraulic fluid into an outer, reservoir tube. In the early days of shock absorbers, direct-acting hydraulic shocks, featuring a twin-tube design, were the norm, but that is no longer the case.

Some automotive shocks are adjustable, allowing you to set them up for a stiffer or softer ride. The piston inside any shock absorber actually has some small holes in it, to let a little bit of hydraulic fluid to seep through. The bigger the holes, the more fluid can slip through. The more fluid that can slip through, the softer the ride will be.

Then there are electronic shocks, which are usually controlled by a button or a switch, while some are self-adjusting on the fly. One way this is achieved is with hydraulic fluid with iron in it, known as ferrofluid. The vehicle's computer sends power to an electromagnet. The magnet acts on the iron in the hydraulic fluid making it stiffer. Other electronic shock systems simply use electronically controlled solenoids to increase or decrease the flow of fluid.

Coil over shock assemblies are used in automobiles equipped with double wishbone or multilink suspension systems. These shock assemblies consist of a shock absorber with a coil spring mounted around it. Due to their appearance, they are often mistaken for strut assemblies.

Some SUVs and luxury cars use air suspension systems. Instead of normal shocks and springs, they use rubber air bags filled with air by a compressor. The coil spring is typically removed and replaced with the air bag; a shock absorber of some sort is still used in conjunction. These provide a smooth ride and ride leveling. If the rear end is loaded from cargo or towing, for example, the compressor will pump more air to the rear air springs to raise up the rear end.  Air ride systems are costly to maintain however. Conversion kits like the ones we offer here at 1A Auto are meant to be a low cost solution to the high price of maintaining the air ride system. The conversion kits will typically replace the air bag with some kind of coil spring.

How do I know if my shocks or struts need to be replaced?

You might need to replace your shocks or struts if you find that your ride quality or your handling is suffering.  To inspect your struts, check visually for dents, punctures, or leaking fluid. Cupping, or uneven wear of the tires, is also a sign of a failed shock or strut. You can also perform a jounce test. If you push down on the hood or trunk, the car or truck should rebound back to its original position. If it keeps bouncing, then your dampers aren't doing their job. 

How many miles do struts last? 

Shocks and struts wear out over time. Some manufacturers recommend that you replace your automobile's shocks and struts every 50,000 to 75,000 miles. Of course, wear can happen more quickly if the shocks and struts are worked hard. If you drive a lot of bad roads, carry heavy duty loads, or go off-roading, then your vehicle's shocks and struts may need to be replaced sooner. Automotive shocks and struts can also be damaged by the elements if they get dented by road debris or corroded by moisture and salt. 

Can shocks and struts leak?

Yes, shocks and struts can develop leaks.  They hydraulic fluid inside the shock or strut can sometimes leak out.  Small leaks are actually somewhat common and not an immediate cause for concern, but larger leaks can be a sign that your shocks or struts need to be replaced.  If you notice a small oil spot on your shock or strut, then it's probably leaking a small amount of fluid.  Over time, this may contribute to reduced ride quality, but you're not likely to experience sudden strut failure.  If most of the shock or strut looks wet and oily, then the shock is losing too much fluid and will work substantially worse. 

How much do shocks and struts cost? 

The cost to replace a shock or strut can vary a lot depending on the model of your vehicle, whether you use original equipment or aftermarket parts, and whether you have the job done by a dealership or an independent mechanic.  Parts can cost anywhere from $50 to $500 and labor cost can run from about $100 to about $500. 

Can I replace shocks and struts myself?

Determined do-it-yourselfers can certainly replace their own shocks and struts. The powerful spring and the pressurized shock absorber do pose some danger if they expand unexpectedly, so it is important to exercise caution. For this reason, we wouldn't blame you if you left this job to the professionals. Replacing coil-over shocks and struts often calls for the use of a specialty tool called a spring compressor. In order to maintain even ride height, you should replace shocks and struts in left-right pairs. 

You will have to raise and secure the car or truck, and remove the wheel where you are working. When removing struts, you may have to remove the brake caliper, and you will have to remove the sway bar link. Then you can set about removing the shock absorber or strut. Start by removing the fasteners at the bottom of the shock or strut. Then remove the ones at the top. Then, if you need to reuse a spring from the old assembly, you will need to compress the spring with a spring compressor. Remove the fasteners from the top of the assembly and slide the spring off the assembly. Then reverse the procedure on the new one. You will have to tighten the fasteners to the vehicle manufacturer's recommended torque specifications. 

Once the new shock absorber or strut is installed, you can reinstall any parts you had to remove to access it, and lower the automobile to the ground. Before you drive the vehicle, check that the ride height looks even. Do the jounce test to make sure the new dampers are working. Then road test the vehicle. Check that the ride and handling feel good and listen for any squeaking or rattling sounds that might indicate loose parts. After working on the suspension, you should get a professional alignment. 

If your car or truck is riding harsh, floating, or losing traction when braking then it may be time to get new shocks or struts. Replacing your shocks and struts is a great way to return the stability and comfort back to your vehicles ride. Here at 1A Auto, you will find a large selection of aftermarket shocks and struts for may makes and models, and at great prices. We carry replacement front and rear shocks and struts, and many different types, from air struts to loaded strut assemblies, to electronic, air and gas shocks, and everything in between from brands you trust like KYB, Monroe and much more. Whether its performance your after or just need a basic replacement, we have you covered.! We also carry many aftermarket shock and strut accessories for your car and truck as well, including mounts, bump stops, brackets, bearings and more. Our replacement shock absorbers, struts and accessories are just what you need to get your vehicle in good working order again.

Need shocks and struts? 

If your car or truck is riding harsh, floating, or losing traction when braking it may be time to get new shocks or struts.  Replacing yshocks and struts is a great way to return stability and comfort back to your vehicles ride.  At 1A Auto, you will find a large selection of aftermarket shocks and struts for many makes and models, and at great prices.  We carry replacement front and rear shocks and struts,in many different types, from air struts to loaded strut assemblies, to electronic, air and gas shocks, and everything in between from brands you trust like KYB, Monroe and much more.  Whether its performance your after or just need a basic replacement, we have you covered! 

We also carry many aftermarket shock and strut accessories for your car and truck, including mounts, bump stops, brackets, bearings and more. Our replacement shock absorbers, struts and accessories are just what you need to get your vehicle in good working order again.