What struts do and why they wear out
Struts are shock absorbers that connect your wheel to the frame and help your car stay level when you turn or hit a bump. Over time — usually between 50,000 and 100,000 miles, though this varies by driving conditions and vehicle — the fluid inside them leaks or the internal parts wear down. When that happens, your car bounces more after hitting a pothole, dips sharply when you brake, or leans hard into turns.
Replacing struts is a job you can do at home if you have basic mechanical skills, the right tools, and a safe way to lift the car. The work takes two to four hours per side, depending on how stuck the old parts are. If you are not comfortable working under a lifted vehicle or do not have access to a jack and jack stands, a shop is the safer choice.
Key Takeaways
- You will need a jack, jack stands, a spring compressor, a strut socket, and basic wrenches — renting or borrowing a spring compressor is common since most people own one only once.
- The hardest part is removing the spring from the old strut; the spring is under pressure and can cause injury if released without a compressor.
- New struts come as complete assemblies or as separate parts (strut body, spring, and mount), and the choice depends on your vehicle and budget.
- The job requires removing the wheel, unbolting the strut from the steering knuckle and frame, and then transferring or installing new components in reverse order.
Tools and parts you will need
Before you start, gather everything. You will need a floor jack and at least two jack stands rated for your vehicle's weight. Never work under a car supported only by a jack. You also need a spring compressor — this tool squeezes the spring so it does not fly apart when you remove it from the strut. Most auto parts stores rent these for $20 to $50 per day.
For fasteners and sockets, have on hand a socket set, a wrench set, a strut socket (a deep socket designed to fit the nut at the top of the strut inside the engine bay), and an adjustable wrench. A torque wrench is useful for tightening bolts to the correct tension, though not absolutely required if you are careful. You will also need new struts — either complete assemblies or individual parts — and possibly new strut mounts, which are rubber and metal pieces that sit between the strut and the frame.
Check your vehicle's manual or a parts website to confirm whether your car uses complete strut assemblies or whether you need to transfer the spring and mount from the old strut to the new one. This varies widely by make and model.
Removing the old strut
Start by loosening the lug nuts on the wheel while the car is still on the ground, then lift the vehicle safely with the floor jack and find it on jack stands. Remove the wheel completely. You should now see the strut running from the top of the steering knuckle (the part that holds the wheel) up into the engine bay.
Unbolt the strut from the steering knuckle — usually two or three bolts. These bolts often seize from rust or age; spray them with penetrating oil and wait 10 to 15 minutes if they are stuck. Once those bolts are out, go to the engine bay and unbolt the strut from the top. You will see one or more nuts holding the strut mount to the frame. Remove these, and the strut assembly will come free.
Set the old strut in a safe place. If you are transferring the spring to a new strut body, you now need to compress the spring and remove it. Clamp the spring compressor onto the spring following the tool's instructions — usually you tighten it until the spring is squeezed and no longer pushing on the mount. Then unbolt the center nut holding the mount to the strut body. The spring will stay compressed; carefully remove the mount, spring, and any other parts you need to keep.
Installing the new strut
If you bought a complete strut assembly, you can skip the spring work. If you are reusing the spring, slide it onto the new strut body, then reinstall the mount and tighten the center nut. Slowly release the spring compressor — the spring will expand and seat itself on the new strut. Remove the compressor.
Carry the new strut to the wheel well and guide it up into position. Start the bolts at the top (in the engine bay) first, then move to the steering knuckle bolts at the bottom. Tighten all bolts snugly, then use a torque wrench to tighten them to the specification in your manual — this is usually between 50 and 150 foot-pounds depending on the bolt. Reinstall the wheel and lower the vehicle.
Repeat the process on the other side. Most mechanics replace struts in pairs (both front or both rear) to keep the suspension balanced, even if only one side is worn.
When to replace strut mounts and springs
The strut mount is the rubber-and-metal sandwich between the strut and the frame. It wears out over time and can cause clunking noises or a rough ride even after new struts are installed. If your mount is cracked, compressed unevenly, or more than 10 years old, replace it while you have the strut out — the labor is already done, and the part costs $30 to $100.
Springs last longer than struts but can sag or break. If your car sits lower on one side than the other, or if you hear a metallic clang when you hit a bump, the spring may be broken. You can replace just the spring without replacing the strut, but if the strut is also worn, replace both. Buying them separately is usually cheaper than buying complete assemblies, but it requires more disassembly work.
Common mistakes and how to avoid them
The most dangerous mistake is releasing a compressed spring without a compressor. The spring can launch with enough force to cause serious injury. Always use the tool, and always follow its instructions exactly. A second common error is forgetting to tighten the top bolts in the engine bay — these are straightforward to miss because they are out of sight. Before you lower the car, double-check that all fasteners are tight.
Another frequent problem is not replacing both struts at the same time. If one side is worn and the other is not, replacing only one will create an imbalance that makes the car handle poorly and can wear out the new strut faster. Finally, do not reuse old strut mounts if they look compressed or cracked. A worn mount will transfer vibration to the frame and defeat the purpose of new struts.
When to call a shop instead
If the bolts are severely rusted and will not budge even after soaking with penetrating oil, a shop has air tools and heat that can remove them without stripping them. If you do not have safe jack stands or a level, solid surface to work on, a shop is safer. If the spring compressor rental is not available in your area, or if you are uncomfortable working under a lifted vehicle, a professional job is the right call.
A shop typically charges $300 to $800 per strut for labor plus parts, depending on the vehicle and location. This cost includes the time to remove stuck fasteners, the proper equipment, and a warranty on the work. For many people, the peace of mind and safety of a professional installation outweighs the cost savings of doing it yourself.
Frequently Asked Questions
Can I replace just one strut?
Technically yes, but it is not recommended. Replacing both on the same axle (both front or both rear) keeps your suspension balanced and prevents uneven wear. If only one is broken, the other is likely worn too and will fail soon after.
How do I know if my struts are actually worn?
Signs include the car bouncing several times after hitting a bump, excessive body roll when turning, or the front end dipping sharply when you brake hard. You can also push down on each corner of the car — if it bounces more than once or twice, the struts are likely worn.
Do I need a torque wrench?
A torque wrench ensures bolts are tight enough to hold but not so tight that they strip or break. You can work without one if you tighten bolts firmly and evenly, but a wrench is cheap to buy or borrow and takes the guesswork out.
What is the difference between a strut and a shock absorber?
A shock absorber only dampens movement. A strut does that plus provides structural support for the suspension and holds the spring. Most cars use struts in front and shocks in back, though some use shocks all around.
How long do new struts last?
Most struts last 50,000 to 100,000 miles. This depends on driving conditions — rough roads, potholes, and heavy loads wear them faster. Regular inspection every 50,000 miles helps you catch wear early.