The steering linkage is composed of all the parts of the steering system that connect the steering wheel to the front wheels (see Figure 16-1). When you turn your steering wheel, the steering linkage causes your front wheels to respond by moving in the proper direction. The principal parts of the steering linkage are the tie rod ends, ball joints, and control arms.
Tie Rod Ends
As you can see in Figure 16-1, the tie rod ends are a type of ball socket assembly located where the steering linkage connects to the wheels. As the two parts of the linkage move against each other, the grease in the tie rod ends cushions them. The grease keeps the parts moving freely and prevents friction that would wear them away.
The steering linkage actually connects to the wheels, which are held in place by a spindle that goes through the wheel and is attached to one or two control arms, or steering arms that allow the wheels to turn in any direction. To keep things moving freely, ball joints are located at points where movement takes place.
Ball joints are important parts of the steering systems on all vehicles. A ball joint is a ball socket assembly that attaches the steering knuckle to the suspension system. The ball joint allows for pivotal and rotational movement of the wheel as it moves up and down and is steered left to right. You can see where ball joints are located in Figures 16-6, 16-10, and 16-15, whichshow various configurations.
Car smarts: Some steering system components are filled with grease to cut down on friction and keep the parts they protect from wearing away prematurely. In the past, these components needed the grease replenished at regular intervals. Almost all of today's vehicles (with the exception of a few SUVs, trucks, and specialty vehicles) have lifetime lubrication systems that are designed to operate for the life of the vehicle without the need for additional lubrication.
From Auto Repair for Dummies, copyright © 2009 by Wiley Publishing, Inc., Indianapolis, Indiana. Used by arrangement with John Wiley & Sons, Inc.