Steering Knuckles

Steering knuckles support the wheel and tire, brakes, and sprung weight of the vehicle. A steering knuckle can be mounted in a variety of ways for both front and rear suspensions. Figure 6-29 shows an example of a common steering knuckle configuration. The steering knuckle also has an attachment point for the outer tie rod end. A wheel bearing or set of bearings mount to the steering knuckle to provide the mounting of the wheel hub. Steering knuckles are also sometimes called spindles. The spindle portion of the steering knuckle is where the wheel bearings and brake components are mounted. The spindle supports those components and allows the wheel to rotate on the wheel bearings.

Stabilizer Bars. Stabilizer bars, also called sway bars or anti-roll bars, reduce body roll. These steel bars attach to the lower control arms or axle assembly and the body or frame. When the vehicle body starts to lift while cornering, the bar tries to move with the body. Since the outer ends of the stabilizer bar are connected to the control arms or axle, and the control arms cannot move upward, it forces the stabilizer bar to pull the body back down, limiting body roll. An illustration of a stabilizer bar is shown in Figure 6-30.

Figure 6-31 shows how the stabilizer bar is connected to the control arm. Some vehicles have adjustable stabilizer bar links, while some modern sports cars use electronic anti-roll systems to reduce body movement. Regardless of the type, broken stabilizer bar links will cause excessive body roll while cornering.