Toe, Caster, and Camber - Aligning Your Vehicle's Wheels

The straighter your car's tires are aligned, the longer they'll last and the more responsive they'll be to your steering commands. Under ideal circumstances, the wheels should be be directed straight ahead, parallel to each other and perpendicular to their respective axles. The problem is, they periodically edge out of alignment and need to be adjusted. Otherwise, you'll notice premature tread wear, which means you'll need to replace the tires sooner. You'll also notice pulling, vibrating, or a sluggish response while you're on the road.

Wheel alignment is primarily based on three factors: toe, camber, and caster. Each of these factors addresses the angles of your vehicle's wheels, though they do so from different perspectives. This article will introduce you to toe, camber, and caster, so you'll understand what might be causing your treads to wear prematurely.

Proper Toe Alignment

In terms of tread wear, toe has a more significant effect than camber or caster. Toe is a measurement of the angle in which your tires are pointing when viewed from directly above. As noted, your tires should be aligned so they are parallel to one another. This is known as zero toe. If the front of your tires point inward toward each other, there is "toe-in." If the back of the tires point inward, there is "toe-out." Both circumstances will cause a feathering pattern in the treads.

Because your car's suspension system has a bit of "give," the alignment of your wheels will change slightly when you drive. For this reason, your mechanic will align them with a small amount of "toe-in" or "toe-out" in order to offset the effect.

Proper Camber Alignment

Camber reflects the manner in which the tops of your wheels tilt when viewed from the front. If the tops tilt inward toward the center of your vehicle, camber is said to be negative. If they tilt outward, it is said to be positive. In both cases, you'll eventually notice premature wear on the shoulders of the treads.

Similar to toe, the tilt of your tires changes slightly when you drive. In fact, these tiny changes occur continuously as you drive over bumps and dips. This is due to your suspension system; the struts and arms move to compensate for variances in the road. Their movement causes changes in camber.

Proper Caster Alignment

Caster measures the tilt of your steering axis when you are looking at it from your vehicle's left or right side. The ideal setting is when the axis is perpendicular to the road. If it is tilted toward the rear of your car, caster is said to be positive. If it tilts forward, it is said to be negative.

Unlike toe and camber, caster does not have a direct influence on the wear of your treads. Instead, it affects steering response. Even though the ideal setting is perpendicular, mechanics will usually set camber slightly positive. The reason is that doing so improves the response of your wheels to your steering commands without sacrificing stability.

The Importance Of Periodic Checks

The alignment of your vehicle's wheels will change as parts in the suspension system wear out. These parts include the struts and control arms, which play an important role in maintaining the proper alignment. Thus, plan to have a mechanic align your wheels on a regular basis (once a year is usually sufficient). If you neglect to do so, your treads will wear down prematurely, needlessly forcing you to invest in a set of replacement tires.