How to change a strut mount​?

How to change a strut mount?
Clunking noises over bumps and vibrations in the steering wheel ruin your drive. You suspect worn suspension parts but dread the mechanic’s labor bill. With the right guidance, you can tackle this repair yourself.

To replace a strut mount, safely jack up the vehicle, remove the entire strut assembly, use heavy-duty spring compressors to relieve tension on the coil spring, remove the top nut, swap the old mount for the new one, and reinstall the assembly.

Replacing this part restores the handling and quiet ride of your car. I will walk you through the safety steps and tools needed to get the job done right without hurting yourself.

What is a Strut Mount? And Why is it Important?

You might think the shock absorber does all the work, but the mount is just as critical. Without it, the metal strut rod would hammer directly against the car body with every turn of the tire.

A strut mount is a component, usually made of a rubber insulator bonded to a metal plate, that attaches the suspension strut to the vehicle’s chassis. It supports the car’s weight while absorbing road noise and vibration.

I spend time on the GSW Autoparts production floor, and I’m always impressed by the engineering in these small parts. A strut mount is like a sandwich. The "bread" is the metal plate, and the "meat" is a high-density rubber block.

This rubber is vital. We test our rubber formulas to ensure they withstand extreme heat from the engine and freezing cold in winter. Its main job is isolation. As your tire rolls over rough asphalt, high-frequency vibrations are created. If the strut were bolted directly to the metal frame, your teeth would chatter. The mount absorbs that energy.

For front struts, there is an extra layer: the Strut Bearing. Because front wheels steer, the strut needs to pivot. The mount contains (or sits on top of) a bearing that allows this rotation. Without it, your steering would bind and snap back. It’s important because a failed mount means metal-on-metal contact, which destroys ride quality and damages the strut tower.

Key Assembly Parts:

Why Strut Mounts Fail And How to change strut mount?

Understanding why they break helps you prevent future issues. Usually, it’s a mix of age, environmental damage, and physical impact.

Strut mounts fail due to rubber degradation from age and heat, corrosion from road salt, and impact damage from potholes. To replace them, you must remove the strut from the car and disassemble it on a bench.

I remember inspecting a return from a customer in a coastal area. The metal plate of the mount had rusted completely through, and the rubber had separated from the steel. Saltwater kills suspension parts. But even in dry climates, rubber dries out. After 5 to 7 years, the rubber loses its elasticity. It becomes hard and brittle. When you hit a pothole, instead of squishing, it cracks.

Another common failure is the bearing. The grease inside dries up, or the plastic race cracks. I had a case where a customer complained of a "creaking old door" sound every time he turned the wheel. That was the strut bearing ground to dust.

To replace it, the process is involved. You cannot change it while the strut is still on the car because the coil spring is pushing up against it with thousands of pounds of force. You have to take the whole "leg" (strut assembly) out.

Common Causes of Failure:

• Heat Cycles: Engine heat cooks the rubber.
• Oil Leaks: Motor oil leaking onto the rubber softens and dissolves it.
• Impact: Hard hits compress the rubber beyond its limit.
• Age: Natural oxidation and cracking over time.

How to replace strut mount: Step-by-Step

This is the critical part of the guide. Pay attention to the safety warnings about the coil spring.

The process involves lifting the car, removing the wheel and sway bar link, unbolting the strut from the knuckle and the tower, compressing the spring until loose, swapping the mount, and re-torquing to spec.

I’ve seen DIY mechanics try to do this without spring compressors. Do not do that. The top nut holds back the spring tension. If you spin it off without compressing the spring, the mount becomes a projectile.

Step-by-Step Guide:

1. Prep: Park on level ground. Loosen lug nuts. Jack up the car and support with stands. Remove wheel.
2. Disconnect Bottom: Locate the sway bar link attached to the strut. Remove the nut and push the link aside. Unclip brake lines. Remove the two large bolts connecting the strut to the steering knuckle.
3. Disconnect Top: Open the hood. Locate the three (usually) bolts holding the mount to the tower. Remove them. Hold the strut so it doesn’t fall and damage your CV boot. Pull the assembly out.
4. Compress Spring: This is the most important step. Hook your spring compressors onto the coils. Tighten them evenly. Crank until the spring is loose and there is a gap between the spring and the mount.
5. Swap Parts: Remove the center shaft nut. Take off the old mount and bearing. Check the spring isolator rubber—replace if torn. Install the new GSW Autoparts mount and bearing.
6. Reassemble: Tighten the center nut. Release the spring compressors slowly. Ensure the spring end sits correctly in the groove. Reinstall the strut in the car.

Tools Checklist:

• Floor Jack & Stands
• Socket Set (usually 10mm to 24mm)
• Spring Compressor (Rentable at auto parts stores)
• Torque Wrench
• Breaker Bar

When is the Right Time to Replace a Strut Mount?

You don’t want to wait until the mount separates completely and dents your hood. Timing is money, especially regarding labor.

The best time to replace strut mounts is whenever you replace your struts (shock absorbers), typically every 50,000 to 80,000 miles, or immediately if you hear clunking noises or see cracked rubber.

I advise all our wholesale partners to sell "complete kits." It makes zero financial sense to pay a mechanic for 3 hours of labor to change a worn strut cartridge but put the 10-year-old mount back on.

Think about it: The labor is identical. To change the strut¹, you have to take the mount off. If you reuse the old mount² and it fails in 6 months (which is common because the new stiff strut puts more stress on old rubber), you have to pay the labor all over again just for that part.

Visual Inspection:
Pop the hood. Look at the strut towers.

• Is the rubber cracked like dried mud?
• Is the center bolt off-center?
• Is there rust around the plate?
• Does the rubber look "squished" or collapsed compared to photos of a new one?

If you see these, change them. Also, do the "bounce test." Push down hard on the corner of the car. If it bounces more than once, the strut is bad. If you hear a squeak or clunk while pushing, the mount is bad.

Replacement Interval Guide:

• 50,000 Miles: Inspect rubber condition.
• 75,000 – 100,000 Miles: Proactive replacement with new struts.
• Anytime: If you replace coil springs or struts.

Conclusion

After replacement, a static inspection is performed to observe whether the top mount rubber is evenly stressed and whether the center axis is centered, without any offset or twisting.
Secondly, a dynamic test is conducted: after starting the vehicle, turn the steering wheel left and right to feel if the steering is smooth and without any sticking.

While driving, test the shock absorption effect on bumpy roads; the absence of any "clunking" noise indicates a successful installation.

Furthermore, a four-wheel alignment must be completed within 48 hours of replacing the top mount to correct camber and caster parameters, preventing uneven tire wear and vehicle pulling to one side.

Following these points ensures safe maintenance, restores the stability of the suspension system, and extends its overall lifespan.
GSW’s Strut Mounts are of excellent quality and offer top-notch service, making them an excellent partner.

Replacing a strut mount is a challenging but rewarding job that ensures your car drives safely and quietly. Always use caution with spring compressors and replace mounts in pairs to keep your suspension balanced.

About the Author

Root is a Content & Operations Specialist at GSWAUTOPARTS with 5 years of industry experience. With the advantage of being close to the production floor, Root excels at documenting product details and manufacturing processes. He focuses on translating technical insights about rubber and chassis parts into clear, useful information for customers.