Front-end alignment is one of the most baffling dynamics of a classic Mustang, ranking somewhere behind air conditioning and automatic transmissions. Like cold air and automatics, front-end alignment is a mystery for most of us because we really don't understand what's going on under there. With blind faith and abundant prayer, we hand over our keys to the service technician who pulls our Mustang onto the alignment rack. We leave 30 minutes later wondering what was performed while we were sipping on that bad cup of coffee and watching Jerry Springer in the waiting room.
That is, if your alignment shop can even handle a vintage Mustang alignment job. It's all too common these days to find young alignment technicians who have been trained only for today's newer cars, so they are unfamiliar with older suspensions and their alignment techniques. Also, we've run into shops that claim they don't have specs for '60s cars--or maybe that was just an excuse to cover up for the technician's lack of expertise on those cars.
A vintage Mustang front-end alignment isn't really a mystery. It is little more than the proper geometry of the front wheels and tires as they relate to the pavement. When the alignment is off, tire wear increases as can your struggle with the steering wheel. We've all been there at one time or another. The steering wheel is at 10 o'clock with the front wheels straight ahead. How many times has a lazy technician told you, "Oh, just remove and recenter the steering wheel
" because they neglected to properly set the toe? Or the frustration of that drift to the right on a straight and level roadway. The greatest insult is the extraordinary tread wear on a new set of BFGoodrich Radial T/As.
We visited with Marlon Mitchell of Marlo's Frame & Alignment in Chatsworth, California, for an education on front-end alignment for vintage Mustangs. Marlo's has been aligning front ends for several decades in Southern California, so they're very familiar with older Fords.
We're going to set you straight on vintage Mustang front-end alignment so you will be ready for that next visit to the alignment shop. Those of you with other Fords and Mercs can learn from this too.
Caster is adjusted on ’65-’66...
Caster is adjusted on ’65-’66 Mustangs and ’60-’65 Falcons and Comets by changing the number of shims on the upper control arm. If you have more shims on the rear bolt than you have on the front bolt, the upper ball joint is moved forward, which moves the wheel/spindle forward. If you have more shims on the front bolt, this moves the spindle aft. The strut rod is a fixed position part for ’65-’66.
For ’67-’73 Mustangs and Cougars,...
For ’67-’73 Mustangs and Cougars, plus other Ford compacts and intermediates, caster is set by adjusting the strut-rod nuts. Pull the strut forward and you move the spindle (wheel) forward. Move the strut aft and you move the spindle aft. The upper control arms are not shimmed from ’67-’73.
Caster is the first check...
Caster is the first check and adjustment. Marlon Mitchell at Marlo’s Frame & Alignment checks caster using a traditional caster/camber bubble gauge. Mitchell runs the wheels 20 degrees out, 20 degrees in, then back to center for the caster check. This ’68 Mustang is showing 2 degrees of positive caster on the left side, which is perfect. The plate on which the tire rests shows the number of degrees the wheel moves from lock to lock. Typical movement is around 20 degrees each way.
For ’65-’66 Mustangs and ’60-’65...
For ’65-’66 Mustangs and ’60-’65 Falcons and Comets, caster is adjusted at “A,” the upper control arm, using shims. Camber is also adjusted at “A” using shims. The strut rod (B) is non-adjustable. Toe is set using the tie-rod ends (C).
For ’67-’73 Mustangs, Cougars,...
For ’67-’73 Mustangs, Cougars, Falcons, Comets, Fairlanes, and Torinos, camber is adjusted by loosening the lower control arm nut and moving the eccentric, which moves the lower control arm in and out. Move the arm in for positive camber, out for negative camber. This particular eccentric is installed incorrectly. The bolt head should always be installed toward the rear of the vehicle. Why? Because the crossmember will keep the pivot bolt in place should the nut work loose. This is an important safety issue. Most take the lazy way out and turn this bolt around during control arm replacement for ease of installation.
Toe is set by turning the...
Toe is set by turning the tie-rod sleeve (arrow A), which runs the tie-rod ends in or out (double-headed arrows). Each side is independently adjusted.
Toe is checked by measuring...
Toe is checked by measuring the tires’ inboard sidewalls fore and aft. Mitchell measures front (shown), then aft. Notice the absence of electronics here. Mitchell and his father do it the old-fashioned way with exceptional results.
The first step in a front-end alignment is caster check and adjustment. Caster, as the name implies, is how the wheels caster in relation to each other. Because most roads have a crown at the middle for water runoff, an alignment specialist will set the caster where the right wheel is slightly ahead of the left, which makes the vehicle wander ever so slightly toward the center of the road, which keeps the vehicle on the road and off the shoulder. Where caster becomes a pain at times is when we're on the freeway where there is no crown and the vehicle tends to drift toward the middle.
Caster is adjusted two ways depending on model year. Mustangs from '65-66, and Falcons and Comets from '60-65 have their caster set by the number of shims used on the upper control arms. The number of shims determines the angle of the control arm in relation to the shock tower. The angle of the control arm determines spindle positioning.
For '67-73, caster is set by adjusting the strut-rod adjustment nuts, which move the strut rod, lower control arm, and spindle fore and aft.
Camber is the angle of the tire and wheel in relation to the pavement, adjusting it by moving either the upper or lower control arms, which controls the angle of the tire/wheel assembly. For '65-66 Mustangs and '60-65 Falcons and Comets, camber is adjusted with shims on the upper control arms. Add shims and you increase camber, which pushes the top of the tire out. Decrease the number of shims and you reduce camber, which brings the top of the tire inboard.
For '67-73 Mustangs, Cougars, Falcons, Comets, and Fairlane/Torinos, camber is adjusted using an eccentric on the lower control arm. The upper control arms are in a fixed position and not adjustable.
For the street, camber should be nearly dead-on (tread at 12 and 6 o'clock), which means the tire tread is seated perfectly on the pavement when the vehicle is at rest. Canyon and road racers need a pinch of negative camber, which puts more tread in contact with the road in hard cornering.
Toe is the relationship between the tire/wheel and the steering linkage. It also affects the way the tire tracks. Adjust toe by screwing the tie-rod end sleeves and running the tie-rod ends in or out. Typical toe for a classic Mustang is a pinch of toe-out, which helps the vehicle track nice and straight. A little bit of toe-out provides stability. And yes, it will affect tire wear to a certain degree. Because toe-out is ever so slight, you'll never notice.