Steering Knuckle

In a non-drive suspension, the knuckle typically has a spindle where the brake drum or brake rotor attaches. The wheel/tire assembly is then attached to lug studs and rotates freely on the spindle shaft. On the other hand, in a drive suspension, there is no spindle on the knuckle. Instead, there is a hub where the bearings and drive mechanism shaft are affixed. The wheel assembly in a drive suspension rotates as dictated by the drive shaft or half-shaft, and it does not turn freely by itself unless disengaged from the transaxle or differential. Additionally, a driven suspension can also be steerable, known as a drive/steer arrangement.