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MacPherson strut

The Macpherson strut is a type of car suspension system widely used in modern vehicles. It can be used for both front and rear suspensions, but is usually found at the front, where it provides a steering pivot (kingpin) as well as a suspension mounting for the wheel.

It consists of a small subframe or arm at the bottom which provides a bottom mounting point for the hub or axle of the wheel. This subframe provides both lateral and longitudinal location of the wheel. The upper part of the hub is fixed to the strut proper, which extends upwards directly to a mounting in the body shell of the vehicle. This type of suspension is only applicable to monocoque (unitary) body construction. The strut will usually carry both the coil spring on which the body is suspended and the shock absorber, which is usually in the form of a cartridge mounted within the strut. The strut also usually has a steering arm built in. It is because the whole assembly is very simple and can be preassembled into a unit that is has become almost ubiquitous with manufacturers. In addition to its simplicity and lower cost, it has few vices in respect of handling. Its only real drawback is that it tends to transmit noise and vibration from the road directly into the body shell, giving higher noise levels and a "hard" feeling to the ride compared with older systems such as wishbones.