Top mount (strut mount) for your car

The strut mount connects the suspension strut with the bodywork, damping the vibrations of the shock absorber and allowing the front struts to rotate to enable steering movement. Therefore, front strut mounts are equipped with a roller bearing in their center. Rear strut mounts do not rotate as the rear axle is rigid and does not steer. For the sake of distinction, rear strut mounts are alternatively called support bearings.

Essence of the strut mount

Cars are built to be propelled safely and comfortably within the permitted parameters. A driver is often unaware of the enormous powers working in the car. If suspension struts wouldn't be connected to the bodywork by a buffering element, occurring forces would cause considerable stress to the plating. To prevent the suspension strut from breaking off, its connection point must be a very sturdy construction, which would make the car heavier. A flexible, elastic connection between strut and bodywork is therefore the ideal solution.

Construction of a strut mount

A strut mount is a half-elastic module of rubber and plastic. It is strengthened by an inner steel ring. The front bearings have an integrated roller bearing, which is absent in the rear strut mounts.

Wear of a strut mount

Strut mounts permanently absorb the vibrating effect of the struts. At every bounce, several tons weigh down on the small rubber element. Over time, the elasticity of the bearing gives out. The connection between strut and bodywork is no longer optimal and develops a backlash. This could cause several effects:

• the car is noisy, especially on a bumpy road
• one-side tyre's wear
• the car does not maintain its track.

To make certain if the strut mount is actually defective, the car must be placed on a ramp. Subsequently the strut is shaken manually. If it can be moved to and fro, the strut mount is definitely worn.

Life span and replacement of a strut mount

The life span of a strut mount is approximately 100.000 km within normal driving style. Replacement of a strut mount requires disassembly of the suspension strut which is only possible with special tools such as the spring compressor.

All attempts of disassembling a strut mount without a suitable spring compressor are mortally dangerous!

The shock absorbers' life span is more or less equal to that of the strut mounts. Therefore replacing all suspension elements on occasion of the strut mount replacement is convenient. In doing so, a perfect condition of the suspension for the next 100.000 km is re-established.

Other sensible measures when replacing a strut mount

Disassembling a strut mount constitutes an extensive repair, not really difficult, but it's a lot of work. When you are disassembling the strut mounts anyway, it is an excellent opportunity to have a look at other wear parts, such as:

• axle sleeves
• steering shaft sleeves
• ball joint
• brake discs and linings
• wheel bearing

It would be annoying, having to start all over again right after the big repair by replacing a strut mount, just because another component turns out to be defective. In view of the cheap prices for spare parts, be certain to replace everything that makes sense on occasion of a repair in this magnitude.

Prices of strut mounts

The strut mount is amazingly cheap. A set for the front axle costs between 15 and 30 euro (c.£13 – £27). In smaller and lighter cars a strut mount is cheaper. Heavier and faster cars need more stable spare parts, and that is why the prices differ. Strut mounts and support bearings are always replaced in pairs. Their wear occurs both gradually and simultaneously. Replacing only one bearing would impair rather than improve the driving quality. The rear support bearings are replaced as a pair as well. New strut mounts will bring you one step closer to passing your upcoming MOT inspection.