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What Does a Steering Knuckle Do?

by Andrea Stein

Vehicle suspension refers to the system of linkages, springs and other components that facilitates breaking and road handling. A steering knuckle is a key part of this system.


A steering knuckle is a stub axle that is used as a connection point between the tie rod and wheel. Steering knuckles also connect the lower and upper ball joints in A frame vehicle suspensions. Disk-brake systems use steering knuckles as a brake-caliper mount.

Macpherson Strut System

Control arms connect other suspension parts to the vehicle's frame. Macpherson strut systems use only the lower control arm, which supports the coil spring, and attaches to the steering knuckle via a ball joint. The upper strut is used as a swivel for the steering knuckle and supports the vehicle's suspension system.


Steering knuckles possess a long life span and typically outlast the components they are attached to. Steering knuckle damage typically results from direct collision damage.

About the Author

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