Front Steering Knuckle: Description and Operation

DESCRIPTION
The steering knuckle is a single casting with legs machined for attachment to the front strut assembly on the top, lower control arm ball joint on the bottom, and steering linkage on the trailing end. The steering knuckle also has two machined, drilled and tapped legs on the leading end casting to support and align the front disc brake caliper adapter.

The knuckle supports the wheel bearing and hub. The wheel hub is pressed into a sealed-for-life wheel bearing that is pressed into the steering knuckle. A retainer plate also holds the bearing in place. The hub supports the driveshaft outer Constant Velocity (C/V) joint. Each is splined and meshes in the center of the hub. The outer C/V joint is retained to the hub using a nut. The nut is locked to the outer C/V stub shaft using a nut retainer and cotter pin.

The wheel bearing is a Unit 1 type cartridge bearing that requires no maintenance. The wheel bearing can be serviced separately from the hub.

The hub has five studs pressed into its flange.

OPERATION
The steering knuckle pivots with the strut assembly between the lower ball joint and the pivot bearing in the strut assembly. The steering gear outer tie rod end connects to the trailing end of each knuckle, allowing the vehicle to be steered.

The center of the knuckle supports the hub, wheel bearing and axle shaft.

The hub and wheel bearing work together. The wheel bearing has internal bearings that allow the hub to rotate with the driveshaft and the tire and wheel assembly. The hub's five studs mount the tire and wheel to the vehicle.