Ford Motor Company completely redesigned the Mustang for the 1974 model year, calling it the Mustang II. The front suspension and steering system were upgraded to include rack-and-pinion steering and coil springs in between the upper and lower control arms. This front suspension set-up -- either in original or aftermarket form -- is the basis for many modern hot rods as of 2012. Before servicing your 1974 Mustang II front suspension, you should be aware of the alignment specifications.
Caster is the angle between the top and bottom pivot points of the suspension as viewed from the side. On the Mustang II, these pivot points would be the upper and lower ball joints. Caster affects the geometry of the front wheel in turns. According to Ford, the front suspension in your Mustang calls for positive castor. This means that the upper ball joint is slightly more forward the lower ball joint. The ideal castor for both sides of the car is 7/8 degrees. A minimum of 1/8 degree and a maximum of 1 5/8 degree is allowable.
Camber is the angle of the tire and wheel as viewed front the front of the car. Most vehicles -- the 1974 Mustang II included -- have negative camber built into the front suspension. This means the tops of both the front tires are closer together that the bottoms of the tires. This helps keep the car more stable with minimal tire wear when cornering by keeping more of the tire tread in contact with the road surface. Ford calls for ½ degree of negative camber for both the right and left side of the car. A minimum of ¼ degree to a maximum of 1 ¼ degree is acceptable.
Toe in the angle of the front wheels in relation to a longitudinal plane with the length of the car. Toe-in is a condition in which the front tires are closer to each other at the front. Toe-out mean that the front tires are closer to each other in the back. The alignment specifications for your Mustang call for 1/8 inch of toe-in, with zero toe at a minimum and ¼ inch toe-in maximum.
To adjust the caster angle on your 1974 Mustang II, the strut rod nut must be loosened. The strut rod in attached to the lower control arm from behind. When the rod is moved in or out, the caster angle is changed. To adjust the camber, the upper control arm attachment bolts must be loosened. The mounting holes in the control arm are slotted, allowing slight movement of the arm in or out to obtain the correct degree of camber. The toe on your Mustang is adjusted by loosening the clamp nuts on the outer tie rods, then twisting the tie rods -- which are threaded -- in or out as needed.
