The MacPherson Strut: The Damper Is the Upper Link

Independent front suspension usually needs two wishbones per wheel, a spring and a damper. Earle S. MacPherson, an engineer at General Motors and then Ford, combined the damper, the spring and the upper link into one telescopic strut running from the hub up to the body, with a single lower link at the bottom. His patent was filed in 1947 and granted in 1953. It is cheap, light and compact, and it leaves room across the car for the engine — which is why most small front-wheel-drive cars use it. This rung computes how the wheel's camber changes as the suspension moves, and builds a cardboard front-view model to measure it with a protractor.