What struts do and when they need replacing
Struts are shock absorbers combined with a spring and structural support that hold up the front or rear of your car. They dampen the bounce when you hit a bump and keep your wheels in contact with the road. When they wear out, your car will bounce excessively after hitting a pothole, dip lower on one side, or make clunking sounds over rough pavement.
Most struts last between 50,000 and 100,000 miles, though this varies by driving conditions and vehicle weight. If you drive on rough roads or tow frequently, they wear faster. You will know they need replacing when the ride becomes noticeably softer, the car leans during turns, or you see fluid leaking down the strut body.
Replacing struts yourself is possible if you have basic mechanical skill, a jack, jack stands, and a spring compressor. The job takes three to four hours per side. If you lack tools or confidence, a shop will charge between $400 and $1,200 per axle, depending on your vehicle and whether both sides need work.
Key Takeaways
- Struts combine a shock absorber, spring, and structural support, and they typically need replacement between 50,000 and 100,000 miles.
- You will need a spring compressor, jack, jack stands, and basic wrenches to replace struts yourself; without a compressor, the job becomes dangerous.
- The process involves removing the wheel, disconnecting the brake line and sway bar, unbolting the strut from the knuckle, and compressing the spring to separate the old strut from its spring.
- If you do not own a spring compressor, renting one costs $20 to $40 per day and is safer than attempting to compress the spring by hand.
- Replacing both struts on the same axle at the same time prevents uneven handling and is more cost-effective than replacing one later.
Tools and parts you will need
Gather these items before you start: a floor jack and jack stands rated for your vehicle's weight, a socket set with metric sizes (usually 10mm to 18mm), a spring compressor, a torque wrench, a brake line wrench, a sway bar link removal tool (or a second wrench), and new struts with springs already assembled (called strut assemblies) or separate springs and struts if you are reusing the springs.
A spring compressor is not optional. It holds the spring under tension so you can safely remove the nut that holds the spring to the strut rod. Renting one from an auto parts store costs $20 to $40 per day. Attempting to compress a spring by hand or with a C-clamp risks serious injury if the spring slips.
Buy struts matched to your vehicle's year, make, and model. Many shops sell them as complete assemblies with the spring, mount, and bearing already attached, which simplifies the job. Check your owner's manual or a parts catalog for the correct part number. You may also need new strut mounting bolts, which are inexpensive and worth replacing to prevent corrosion.
Removing the old strut: step by step
Loosen the lug nuts on the wheel while the car is on the ground, then raise the vehicle with the floor jack and find it on jack stands. Remove the wheel. Locate the brake line bracket bolted to the strut and unbolt it using a brake line wrench; do not disconnect the hose itself, just move the bracket aside so the line does not stretch when you remove the strut.
Find the sway bar link bolted to the strut. Use two wrenches—one to hold the nut on top and one to turn the bolt below—and remove it. The sway bar link will hang loose but does not need to be fully removed. Next, locate the two bolts where the strut connects to the steering knuckle at the bottom. Remove both bolts; the strut will now hang only from the three bolts at the top where it mounts to the car body.
From inside the engine bay or trunk (depending on whether you are replacing front or rear struts), remove the three nuts holding the strut mount to the body. Support the strut with one hand as you remove the final nut so it does not fall. Lower the strut out of the car and place it on a workbench.
Separating the spring from the old strut
Install the spring compressor on the spring according to the tool's instructions. Compress the spring until it is no longer pushing on the nut at the top of the strut rod. The nut should turn freely by hand once the spring is compressed enough.
Hold the strut rod steady with a wrench while you turn the nut counterclockwise with another wrench. Once the nut is off, carefully release the spring compressor and remove the spring, upper mount, and bearing from the strut. Keep these parts in order if you are reusing the spring; if you bought a complete assembly, discard the old spring and mount.
Inspect the upper mount and bearing for cracks or excessive wear. If you are reusing the spring, check it for cracks or permanent bends. A damaged spring or mount will cause noise or poor handling even with a new strut.
Installing the new strut and reassembling
If you are reusing the spring, slide it onto the new strut rod, then install the upper mount and bearing. Use the spring compressor again to compress the spring, then thread the nut onto the rod and tighten it to the torque specification in your manual (typically 40 to 60 foot-pounds). If you bought a complete assembly, skip this step—the spring is already attached.
Carry the new strut to the car and guide it up through the wheel well. Align the three mounting holes at the top with the body holes and thread the nuts by hand first. Install the two bolts at the bottom where the strut connects to the knuckle, again threading by hand before tightening. Tighten all five bolts to the torque specification in your manual.
Reconnect the sway bar link and the brake line bracket. Reinstall the wheel and tighten the lug nuts in a star pattern (opposite sides alternately) to avoid warping the rotor. Lower the car to the ground and tighten the lug nuts fully.
Torque specifications and final checks
Torque values vary by vehicle, so check your owner's manual or a repair manual for your specific year and model. Common ranges are 18 to 25 foot-pounds for the strut-to-knuckle bolts, 40 to 60 foot-pounds for the strut rod nut, and 50 to 70 foot-pounds for the sway bar link. Using a torque wrench prevents over-tightening, which can crack the knuckle or strip threads.
After installation, take the car on a short test drive on a quiet road. The ride should feel firmer than before and the car should not bounce excessively. If you hear clunking or the car still bounces, stop and check that all bolts are tight and that the strut is fully seated in the knuckle.
If you replaced only one side, the car may pull slightly toward the side with the new strut because the old one on the other side is softer. This is normal and temporary; replace the strut on the other side as soon as you can to restore even handling.
When to replace both sides at once
Replacing both struts on the same axle (both fronts or both rears) at the same time costs more upfront but prevents uneven handling and saves labor. If one strut is worn, the other is usually not far behind. Replacing only one side leaves you with a soft, worn strut on the other side, which will need replacement within months or a year.
If your budget allows, buy and install both struts in one session. The second strut takes only an hour longer than the first because you already know the steps. A shop will charge less per strut when doing both sides at once because the labor is more efficient.
Frequently Asked Questions
Can I replace just one strut, or do I have to do both sides?
You can replace one, but it is not recommended. The remaining old strut will be softer and wear faster, and your car will handle unevenly until you replace it. Most mechanics suggest replacing both struts on the same axle to restore balanced suspension and avoid a second job in a few months.
What is the difference between a strut and a shock absorber?
A shock absorber only dampens bouncing; a strut does that plus holds up the weight of the car and serves as a structural part of the suspension. Struts are common on front axles and some rear axles. Shocks are used on vehicles with separate springs and are easier to replace because you do not have to compress a spring.
Do I need to get a wheel alignment after replacing struts?
Yes, an alignment is recommended after strut replacement, especially on the front axle. Removing and reinstalling the strut can shift the angle of the wheel slightly. An alignment costs $100 to $200 and ensures your tires wear evenly and the car tracks straight.
How long does it take a shop to replace struts?
A shop typically charges one to two hours of labor per side, so replacing both front struts takes two to three hours. Total cost including parts and labor ranges from $400 to $1,200 per axle depending on the vehicle and whether the shop needs to replace additional components like mounts or bearings.
What happens if I drive with worn struts?
Worn struts reduce your car's ability to stop quickly, increase tire wear, and make the car bounce excessively. In an emergency stop or hard turn, worn struts can cause the car to lean so much that a tire loses contact with the road, reducing control. Replacing them restores safety and handling.