What is a Strut Mount? Everything You Need to Know.

Are you hearing a clunking or knocking sound every time you drive over a bump? A noisy, harsh ride is often a sign that a small but essential part of your suspension, the strut mount, has failed.

A strut mount is the component that attaches your car’s suspension strut to the vehicle’s body. It acts as an insulator to absorb noise and vibration, while also providing a pivot point that allows the wheel to turn for steering.

This crucial part plays a dual role in both your suspension and steering systems. Understanding what it does and the symptoms of failure can help you catch problems early, ensuring a safe, quiet, and comfortable drive. Let’s dive into everything you need to know about this vital component.

What Is A Strut Mount?

While the shock absorber or strut gets most of the credit for a smooth ride, the mount that holds it in place is just as important. It’s the unsung hero of your suspension system.

A strut mount is a robust assembly made of rubber and metal that bolts to the top of a MacPherson strut. It contains a rubber insulator to absorb vibrations and a bearing that allows the entire strut assembly to rotate as you steer the car.

In my 25 years as an automotive parts manufacturer, I’ve seen how the quality of a strut mount can make a world of difference. The two key parts have very different jobs:

• The Rubber Insulator: Think of this as a heavy-duty cushion. Its job is to absorb the constant vibrations and impacts from the road, preventing them from being transferred into the car’s chassis. At GSW Autoparts, we specialise in rubber compounds, and the quality of this rubber determines how quiet your ride is and how long the mount lasts.
• The Strut Bearing: This is a flat bearing (or plate) that sits inside the mount. It allows the entire strut to pivot smoothly and easily as you turn the steering wheel. If this bearing fails, your steering can become stiff or noisy.

You can usually see the top of the front strut mounts by opening your bonnet and looking at the top of the suspension towers on either side of the engine bay.

What Are The Symptoms of A Bad Strut Mount?

Trying to diagnose a strange noise from your suspension can be frustrating. A failing strut mount has several distinct symptoms that can help you pinpoint it as the culprit.

The most common symptoms of a bad strut mount are clunking or popping sounds when driving over bumps, creaking or binding noises when steering at low speeds, vibration, and "memory steer," where the steering wheel is slow to return to centre.

A worn strut mount can no longer do its two jobs effectively. The failure of either the rubber part or the bearing part will produce different, but noticeable, symptoms.

• Clunking or Rattling Noises: This is the most frequent complaint. When the rubber insulator degrades and collapses, it creates a gap. The metal strut rod can then bang against the metal chassis when you go over bumps, creating a loud clunk.
• Creaking, Grinding, or Binding Sounds¹: If you hear a creaking, groaning, or "boing" sound when turning the steering wheel while parked or moving slowly, it’s a classic sign that the strut bearing has seized or worn out. The sound is the coil spring binding and then releasing as it fights the stiff bearing.
• Memory Steer²: This is when your steering wheel doesn’t want to return to the straight-ahead position on its own after you make a turn. A binding strut bearing prevents the suspension from moving freely back to its neutral position.
• Vibrations and Poor Ride Quality³: A collapsed mount can no longer absorb road vibrations, leading to a harsher ride and vibrations felt through the steering wheel. It can also affect wheel alignment, causing uneven tyre wear.

Can You Drive with A Broken Strut Mount?

If you hear that tell-tale clunking, it’s tempting to turn up the radio and hope it goes away. But is it safe to keep driving on a broken strut mount?

While your car will still technically drive with a broken strut mount, it is highly unsafe and not recommended. Continuing to drive will lead to poor handling, unpredictable steering, and will cause accelerated wear to your tyres and other suspension components.

Ignoring a bad strut mount is a bad idea for several reasons. What starts as an annoying noise can quickly escalate into a more dangerous and expensive problem.

1. Reduced Vehicle Control⁴: The mount is a key part of your suspension geometry. When it fails, your wheel alignment is affected, compromising steering response and stability. This is especially dangerous during an emergency manoeuvre or in wet conditions.
2. Accelerated Tyre Wear⁵: The poor alignment caused by a collapsed mount will cause the edges of your tyres to wear down very quickly, forcing you to replace them much sooner than expected.
3. Damage to Other Components: The constant banging and vibration puts immense stress on the strut itself, as well as the ball joints and control arm bushings. This can cause a cascade of failures, turning a single repair into a full suspension overhaul.
4. Catastrophic Failure⁶: In extreme cases, a completely failed strut mount can allow the strut assembly to break free from the chassis. This would cause the suspension on that corner to collapse, leading to a complete and sudden loss of control over the vehicle.

How Much Does It Cost to Replace a Strut Mount?

If you’ve diagnosed a bad strut mount, the next logical question is about the cost of repair. The final bill can vary depending on a few key decisions.

The cost to replace a single strut mount in the UK is typically between £100 and £250. However, it is always recommended to replace them in pairs, and it’s often more economical to replace the entire strut assembly at the same time.

The strut mount part itself is relatively inexpensive, usually costing between £20 and £60. The majority of the cost is for the labour. To replace the mount, a mechanic has to remove the entire strut assembly from the vehicle, which can take 1-2 hours per side.

This is why many garages will recommend replacing the strut (shock absorber) at the same time, especially if your car has over 80,000 miles. The labour is already being done, so you only pay the extra cost for the new strut part. This saves you from having to pay for the same labour again in the near future when the strut eventually wears out. This combined part is often called a "complete strut assembly" or "quick strut." Always replace mounts in pairs (both fronts or both rears) to ensure your car’s handling remains balanced and safe.

Note: Prices are estimates and vary by vehicle. A wheel alignment (£40-£60) is required after the job.

How Do You Replace A Strut Mount?

If you’re an experienced home mechanic, you might be tempted to tackle this job yourself to save on labour costs. However, this is one job where extreme caution is required.

Replacing a strut mount is a complex and potentially dangerous job that should only be attempted by professionals or highly experienced DIYers. The process requires a specialist spring compressor tool, and improper use can lead to serious injury.

The danger lies in the coil spring. It is compressed under thousands of pounds of force. If that energy is released uncontrollably, the spring can fly off with lethal force.

General Steps (Professional Overview):

1. Raise Vehicle & Remove Wheel: Safely lift the car and secure it on axle stands.
2. Remove Strut Assembly: Unbolt the strut from the steering knuckle at the bottom and the strut tower in the engine bay at the top.
3. Compress the Coil Spring: This is the critical step. A spring compressor is used to squeeze the spring, relieving pressure from the top mount. This is extremely dangerous if not done correctly.
4. Replace the Mount: With the spring compressed, the top nut holding the mount can be safely removed. The old mount is taken off and the new one installed.
5. Reassemble and Reinstall: The top nut is tightened, the spring compressors are carefully released, and the entire assembly is bolted back into the car.
6. Wheel Alignment: The vehicle must have its wheel alignment checked and adjusted by a professional after the repair.

Which Strut Mounts Are Suitable for Different Vehicle Models?

Once you’ve decided to replace your strut mounts, you need to make sure you get the right parts. Unlike some generic components, strut mounts are highly specific.

Strut mounts are not one-size-fits-all. Each mount is designed for a specific range of vehicle makes, models, and years to match the chassis bolt pattern, strut design, and load requirements. Using the correct, high-quality part is essential for a safe and successful repair.

As a manufacturer and supplier, we at GSW Autoparts maintain a massive catalogue of parts to serve the diverse global car market. The strut mount for a Ford Focus is completely different from one for a BMW 3 Series or a commercial van. The differences can be in:

• Bolt Pattern: The number and spacing of the top bolts must match the strut tower on the car’s chassis.
• Bearing Design: The internal bearing is designed to handle the specific weight and steering geometry of the vehicle.
• Height and Angle: The physical dimensions are engineered to maintain the correct suspension geometry.

The easiest way to ensure you get the right part is to use your vehicle’s registration number or VIN (Vehicle Identification Number) when ordering from a trusted supplier. This allows the supplier to match the exact OEM (Original Equipment Manufacturer) specification part to your car, guaranteeing a perfect fit and proper performance.

Conclusion

The strut mount is a small but mighty component that is fundamental to your car’s safety, steering, and comfort. Ignoring the signs of failure can be dangerous and costly.