On our car the eccentric will...
On our car the eccentric will be rotated to bring the control arm in toward the centerline of the vehicle. This will bring in the lower edge of the tire, restoring a more nearly vertical condition. Still, a little negative camber is desired in the setting to keep the tire contact patch as flat as possible during cornering. This will aid adhesion and prevent running on the outer sidewall during hard cornering. On earlier cars this eccentric wasn't present and lower control arm position was fixed in this respect. Camber was adjusted by adding or subtracting shims at the upper control arm.
The best way to visualize caster is to picture a shopping cart caster. The pivot of this type of caster, while not at an angle, intersects the ground ahead of the wheel contact patch. When the wheel is behind the pivot at the point where it contacts the ground, it is in positive caster. Picture trying to push a shopping cart and keep the wheel ahead of the pivot. The wheel will continually try to turn from straight ahead. That is what happens when a car has the caster set too far negative. The factory caster setting for classic Ford cars calls for a small amount of positive caster.
The third dimension of our alignment is the toe measurement. This is the difference in the center to center distance between the front of the tires and the back of the tires. It is measured in fractions of an inch and is usually set close to zero, which means that the wheels are almost parallel to each other. Toe-in means that the fronts of the tires are closer to each other than the rears. Toe-out is just the opposite. An incorrect toe-in setting will cause rapid tire wear. For racing purposes, toe-in is subtracted or eliminated to aid quicker response when cornering. However, a vehicle aligned this way won't be much fun to drive on the freeway.
Bushings: Stock Versus Modified
It's a fact that when Ford designed the original suspension many important moveable junctures or pivot points had rubber bushings as original equipment. Both upper and lower control arms were attached to the car using a bushing with a steel center and a rubber jacket. While the rubber dimension of these components reduced vibration and promoted a smoother ride, after a certain amount of time these bushings would begin to compress and come out of round. In addition to losing the correct alignment adjustment, a certain amount of play was created, allowing the component to move around freely-not the best of circumstances for correct vehicle alignment or concise steering. Now there's a great bolt-in alternative from Fly-Ford Racing that gives a near-stock appearance without any suspension or frame modifications.
Here Marlon uses a toe-width...
Here Marlon uses a toe-width bar with the correct setting for a small amount of toe-in dialed in. Because there is a slight disparity between the setting and the spec, an adjustment will have to be made. The total amount of toe-in required will be adjusted for at both wheels, with each contributing to half of the adjustment. That way both tires will wear evenly.
As you can see in this photo...
As you can see in this photo the rubber collar has been eliminated and replaced by oil-impregnated shaft bushings, complete with grease fittings. For exact control and long service life they're the hot set up.
However there is a way to...
However there is a way to retain your stock classic Mustang suspension components and eliminate these OE variables. Marlon Mitchell's Fly-Ford Racing now offers the Blueprint Series of modified stock suspension components. The parts have been upgraded with oil-impregnated shaft bushings, complete with grease fittings. By upgrading the stock rubber bushings with these lubricated hard points, the weaknesses inherent in the original bushing design have been largely eliminated.
Next, the toe-in adjustment...
Next, the toe-in adjustment is accomplished underneath the vehicle by adjusting the length of the tie rods. Since each tie-rod sleeve uses one normal orientation thread and one reverse thread, the tie rod length can be shortened or lengthened simply by twisting the tie-rod sleeve one direction or the other. Once everything is locked down Marlon will recheck all settings to be certain that each one remains in spec.
If you're interested in checking...
If you're interested in checking on your classic Ford alignment at home the tools to do so are now easily available at a reasonable cost form Eastwood. This is its Fastrax Camber Caster Gauge. With this tool you can check camber and caster both home or at the track. It fits most 13- to 18-inch wheels and displays camber in a range of +/- 4 degrees. The range of measurement for caster is -4 to +12 degrees. The Fastrax is zero set for level floors, but adjusts to any surface. The tool is constructed of anodized aluminum, has a locking adjuster, and a calibrated bubble level. The tool includes complete instructions and costs only $199.95.
This tool measures toe-in...
This tool measures toe-in and toe-out on an easy-to-read gauge. To use, set the gauge at the rear of the front tires and take your measurements. Then, transfer the tool to the front of the tires and measure the difference. If necessary, adjust the tie rods in or out half the distance of the dial reading. The cost of this tool is $54.99. In a pinch you can use a tape measure to adjust toe-in specifications but for a more consistent and accurate reading a rigid bar is more desirable.
Just as at Marlon's shop the...
Just as at Marlon's shop the Eastwood gauge attaches directly to the wheel. If you'd like to duplicate the turntable function at home we've heard of folks using cookie sheets on the bottom and vinyl floor tiles with a dollop of grease between the two surfaces. As long as your garage floor is flat you're in business.