Checking and setting alignment...
Checking and setting alignment on early muscle cars is not difficult once you know all the angles.
Since this is Car Craft, where do-it-yourself rules, we just know you secretly harbor an intense desire to get familiar with the basics of alignment and at least know what all those obscure terms mean. This will be especially important the next time you're stranded on a lost Pacific island and the cannibals offer to crown you king if you can dial in the right caster and camber on their Pro Bamboo car. More realistically, what if you want to test your car at the dragstrip after a suspension rebuild, but the alignment shop can only fit you in a week from Wednesday? Just do it yourself and you'll know it's right. We'll cover the basics and get into how to set your own alignment at home with a few simple tools that any good car crafter should have in his toolbox. Even if you don't intend on becoming the neighborhood chassis specialist, at least you can talk intelligently when the bench racing turns to camber and caster. You might actually find this stuff fascinating-we do...
Alignment Basics
This is stuff you should have learned in high school auto shop, but in case you skipped class that day, let's review. Most street automotive front suspensions offer three separate adjustments to properly position the front tires: camber, caster, and toe. Camber is easy to visualize. Face the front of your car and look at the front tires. If the tops of the tires are tilted inward, it is called negative camber. Conversely, if the tops of the tires are tilted outward, that's positive camber. This is a serious tire-wear angle that has a huge impact on vehicle handling in a corner with minimal effect on straight-line driving.
Camber is most easily seen...
Camber is most easily seen from the front of the car looking directly at the front tires. If the top of the tire tilts inward, as in this photo, that's negative camber. If the top is tilted outward, that's positive camber.
Caster is a little less obvious. If you look at a bicycle from the side, the top of the spindle is angled rearward toward the rider. This is an extreme example of positive caster that creates high-speed stability-the effect that allows the rider to let go of the handlebars while the bike tracks straight. Positive caster creates an aligning torque by positioning a portion of vehicle weight behind the tire, which helps position the tire straight ahead. It is this same torque that requires more effort to turn the wheel. The opposite situation is negative caster, where the top of the spindle is tilted forward past its vertical centerline. This creates a grocery cart-like situation, where the wheel centerline is behind the spindle centerline. Negative caster reduces steering effort because the weight moves forward of the spindle vertical center but also detracts from high-speed stability. Virtually all vehicles employ positive caster, but excessive amounts can lead to camber problems, since these two angles directly affect each other.
Toe is perhaps the easiest to understand. Look down at your feet and point your toes inward with your heels angled outward. It's not surprising that this is called toe-in. Substitute front tires for your feet and the effect is the same. The opposite, toe-out, is where the leading edges of the front tires are angled outward. Both of these situations are significant tire-wearing angles, so setting toe is critical to handling and tire life. Toe-out is the worse of the two angles, since a car with excessive toe-out will have skittish steering, often darting to either side of the road very easily. The usual spec is slight toe-in to compensate for angular pressure that forces each tire outward as the car rolls down the road.
 Caster is viewed from the...  Caster is viewed from the side of the tire. Positive caster is when the top of the spindle is tilted backward toward the rear of the car, as in the photo. Negative caster is when the top of the spindle is angled toward the front of the car. Positive caster is always preferable. |  Looking down at the front...  Looking down at the front tires from the front, this is toe-in. Toe-out would be when the leading edges are angled outward. Most street alignments call for a slight amount of toe-in to compensate for outward forces. |  Most bubble alignment gauges...  Most bubble alignment gauges are designed like this one from Intercomp. The two outer scales are for reading positive (left) or negative (right) camber. Caster is read off the center scale using an adjustment knob on the bottom of the gauge. There is also a small level at the end of the gauge to indicate if the gauge is parallel to the ground. |