Alignment Basics
Before we get into the wrench-turning part of the story, we should review exactly what this talk about caster, camber, and toe is all about. Let's start with camber. If you look at a car directly from the front, camber is defined as the inward (negative) or outward (positive) tilt of the top of the spindle. This is a high tire-wear angle and also has a dramatic effect on vehicle handling.
Looking at the car from the side, caster is the forward or rearward tilt of the top of the spindle. If we're looking at the left or driver front tire directly from the side, when the top of the tire tilts back toward the rear of the car, that's called positive caster. This is an angle that promotes high-speed stability and good handling. If the top of the tire is tilted forward, that's called negative caster. This angle reduces steering effort but hurts high-speed stability and should be avoided. Also note that ride height will have a big impact on both of these angles.
Toe is another critical tire-wearing angle and can best be envisioned if you imagine looking straight down on the front tires while standing in front of the car. Toe-in is where the leading edges of the two front tires are closer together than the trailing edges. Toe-out is the opposite, where the leading edges are farther apart than the trailing edges. As you can imagine, excessive amounts of either toe-in or toe-out are not good. Most musclecars generally prefer a small amount of toe-in, along the level of 1 1/32 inch per side for a total of around 1/16 inch.
 Camber is the inward or outward...  Camber is the inward or outward tilt of the spindle as viewed from the front. As you can see from this photo, the inward tilt of the top of the spindle means this is negative camber. |  Looking at the tire from the...  Looking at the tire from the side, caster is the forward or rearward tilt of the top of the spindle. The solid vertical line indicates zero caster, while the dotted line indicates a rearward tilt for the spindle, which generates positive caster. |  Toe is best evaluated looking...  Toe is best evaluated looking straight down on the front tires. This is a radical example of toe-in. Not only does toe affect steering stability, but it is also a serious tire-wear spec. |
This is the early Mustang...
This is the early Mustang camber-adjustment plate from Global West. Note the three different offset holes that adjust the camber. This design will not move, but it requires more effort to adjust than the factory eccentric.
Alignment Angles
Before you get started with adjusting these angles, it's important to make sure all the front-suspension components are in good condition. Before performing the alignment on our Mustang, we converted the Mustang over to a complete Global West Suspension system, but we'll save that how-to for a later story. This ensured that all the front-suspension components were either new or rebuilt and ready for some street fun.
The early Mustang front suspension is a bit different from the typical unequal-length upper and lower control arm suspension where the coil spring is located between the upper and lower arms. The Mustang suspension places the coil spring on top of the upper control arm with a strut rod placed at an angle to the lower control arm that makes its position adjustable for caster.
Camber is the first adjustment Marlon made to the Mustang. Ford uses a round eccentric for the inner pivot point of the lower control arm that is held in place by a single bolt. Loosening the bolt and turning the eccentric moves the lower control arm in (creating positive camber) or out (negative camber)-remember, this is the lower control arm we're talking about. Global West makes a bolt-in eccentric with three offset holes that lock in the camber setting, but it requires you to remove the eccentric every time you change the camber alignment. On GM musclecars, creating negative camber is as simple as adding shims on both studs of the upper control arm. Adding positive camber is even easier, since all you have to do is remove as many shims as necessary.
Changing caster on the Mustang...
Changing caster on the Mustang involves merely changing the length of the strut rod. Decreasing its length adds positive caster by tilting the top of the spindle rearward.
Caster adjustment is also simple on these early Fords. Lengthening the strut rod moves the lower control arm backward, creating negative caster, while shortening the strut length pulls the lower control arm forward, creating positive caster. On GM musclecars, caster is a little more complicated. Adding positive caster involves adding shims only to the rear stud on the upper control arm, while adding shims to the front stud will increase negative caster. This effectively moves the upper portion of the spindle either forward (negative caster) or rearward (positive caster).
Toe changes are also easy, since adjusting the tie-rod turnbuckles will change the length of the steering assembly. Increasing the length of the steering rods will push the tie rods out. Always make the same changes to both sides of the tie-rod ends so each changes the same relative to the centerline of the car. Another variable is whether the car is a front- or rear-steer car. A front-steer car places the steering linkage in front of the true axle centerline, while a rear-steer car places the linkage behind the centerline. Lengthening the steering linkage on a front-steer car will create toe-out, while doing the same on a rear-steer car will create toe-in. Simple, no?