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Tie Score

Steering and the importance of tie-rod ends

In a classic "foot bone connected to the leg bone connected to the hip bone" scenario, the front end in your vehicle not only handles steering chores, it also absorbs bumps, chuckholes, and other road divots in order to keep the wheels doing the steering firmly planted on the ground. Either springs or torsion bars, depending on the vehicle, work in conjunction with the shock absorbers to keep the wheels from bouncing. The steering system connects the wheels to the steering wheel in your hands, and keeps the vehicle steering. Whether by recirculating ball, rack-and-pinion, or some more complicated and exotic system, all of the parts work as a whole to turn the wheels to and fro.

Push or Pull

At the very ends of both sides of either recirculating ball or rack-and-pinion steering systems are sets of tie-rod ends. The tie-rod ends allow for both up-and-down and side-to-side movement as they have ball-in-socket construction much like your hipbone. The tie-rod ends are connected to the steering knuckle. As the steering linkage travels, the tie-rod ends pull or push on their respective steering knuckles and the wheels turn. The second and equally important function of tie-rod ends is to allow for toe adjustments of the wheels.

Free Play

To visualize how the tie-rod ends and knuckles work together and to see what "toe" means, stand up and look down at your toes. Imagine they are the wheels on your car. First turn your feet to the right together, then to the left. That is the function of tie-rod ends and steering knuckles. Turn your toes toward each other, then away from each other. That is toe-in, and toe-out in the world of steering alignment. All of this back-and-forth movement, along with potholes, curb smacks, truck tire retread collisions and other road hazards can cause a tie-rod end to wear out and become loose. Conversely, lack of lubrication can also cause a tie-rod end to wear out and bind up. In fact, the biggest killer of tie-rod ends is lack of regular lubrication.

End Game

Since the tie-rod ends are at the very ends of the steering system, even a little bit of wear can translate into dreaded sloppy steering. The wheel oscillations caused by a worn tie-rod end can be felt in the steering wheel as a wobble or shimmy, and can manifest themselves in odd tire wear usually showing up on the edges as a cupped band. The problem is that these symptoms can also be caused by worn shocks, spent wheel bearings, roasted rack-and-pinion, or any number of worn out front end components. Speed-specific wobble, for example, can also be caused by an out of balance or bent wheel. Either way, checking out the tie-rod ends is easy, and is a great first step on the way to sussing out your front end.