How does the rear shock absorber mount knock?

Anna Tkach

AutoPortal editorial team

548 views 3 min read

The suspension plays a crucial role in ensuring comfort and driving safety. Drivers often complain about extraneous noises when driving on uneven roads, and one of the common sources of such noises is the shock absorber mount. To properly diagnose a malfunction, you need to understand how the shock absorber mount knocks and how this sound differs from other suspension noises.

The suspension is responsible for ride smoothness and driving safety. Car owners often notice extra noises when driving on rough roads, and the source of such sounds is often the shock absorber mount. To correctly identify the problem, it is important to understand how the shock absorber mount knocks and how this sound differs from other suspension faults.

Purpose of the shock absorber mount

The shock absorber mount is a component that attaches the shock absorber to the body and holds it in the correct position during operation. Inside it are rubber-metal bushings and bearing elements. Over time, these components wear out, which leads to knocking sounds.

Nature of the shock absorber mount knock

When the mount wears out, it begins to produce a metallic knock. As a rule, the knock is heard when hitting bumps, speed bumps, or potholes. Drivers describe it as a dull thud coming from the wheel area. It is worth noting: how the shock absorber mount knocks is determined by the tone of the sound. It is not ringing, but rather dull, like a blow inside the suspension. In some cases, the knock is accompanied by vibration on the steering wheel or the body.

Knock of the rear mount

In the rear part of the suspension, the load is distributed differently than in the front. Therefore, how the rear shock absorber mount knocks is more often noticed by the driver when carrying rear passengers or with a loaded trunk. The sound comes from the rear, in the area of the wheel arches. Sometimes it appears not only on uneven surfaces but also during sharp acceleration or braking.

Features of the rear mount knock

If we talk specifically about how the rear shock absorber mount of a car knocks, a distinctive feature will be "dull blows with an echo." They are not like the creaking or squeaking of springs. In frost, the sound may become louder, as the rubber in the mount hardens and absorbs impacts worse. The driver hears knocks from the rear, often it seems that something is rattling in the trunk. However, the cause is precisely the worn mount.

Why the mount knock is dangerous

Leaving such a fault unattended is unacceptable. Driving with a damaged mount can lead to:

accelerated wear of the shock absorber;
damage to the body in the suspension attachment area;
deterioration of handling;
appearance of vibrations and extra noise in the cabin.

The knock always serves as a sign that the component needs inspection and replacement.

How to distinguish the mount knock from other noises

To avoid mistakes, it is worth remembering:

a ball joint knocks more clearly, especially when turning the steering wheel;
stabilizer bushings produce short and frequent knocks;
how the shock absorber mount knocks is rare but noticeable blows when the suspension compresses.

Now it is clear how the rear shock absorber mount of a car knocks and why this sound cannot be ignored. Dull blows when driving over uneven surfaces, especially from the rear, indicate wear of the mount. Timely replacement of the part will preserve the shock absorbers, extend the suspension life, and ensure comfortable driving.