This is the bulletproof spherical...
This is the bulletproof spherical end from Revelation Racing Supply. It replaces the soft rubber factory bushings that were economical and provided a quiet ride. Steering accuracy was not at the top of the engineering list, and the rubber bushings were not particularly durable. Falcon and early Mustang kits run $315 with new strut rods, while kits for '67-and-up Mustangs, Fairlanes, Torinos, and so on, run $245, assuming you reuse your strut rods.
Here's the front end of the...
Here's the front end of the factory strut-rod arrangement typical of many vintage Ford vehicles. Notice the two rubber bushings are beginning to crack and decompose. You can tell these bushings have already been replaced at least once during the forty-year lifetime of this vehicle, because we've seen equivalent bushings in far worse shape than this.
On most classic Ford cars, the front strut rod positively locates the lower control arms. In addition to keeping the lower arm in place during vehicle movement, it also provides for adjustment of vehicle suspension caster, a critical factor of a correct frontend alignment.
In the factory arrangement, the rear of the strut is attached to the lower control arm, while the front end of the strut is held in place by two rubber bushings and washers that sandwich the forward strut-mounting point. Caster adjustment is achieved by moving the rod forward or back, thus changing the location of the lower ball joint in relation to the upper ball joint. The forward end of the rod is threaded, and to accomplish caster adjustment, the washers and bushings are moved along the threads to the desired position, moving the lower ball joint, and then locked into place between two jamb nuts. The rubber bushings also help cushion the transfer of road impacts from the suspension to the chassis of the car, allowing for a quieter and smoother ride.
The downside to this factory arrangement is that the rubber bushings allow strut-rod movement forward and back during vehicle motion. They compress and expand as the wheel hits an imperfection, such as a bump or pothole, and the vehicle alignment changes as the caster angle is moved to and fro. For precise steering, whether for road racing or to create the safest possible vehicle for street use, this condition must be eliminated.
The good news is that the suspension-upgrade experts at Revelation Racing Supply (RRS) now offer two solutions to this problem. For those interested in the ultimate high-performance solution, the rubber bushings are replaced with a spherical end which allows the strut rod to move up and down along with the vehicle suspension. However, it eliminates any movement of the rod forward or back. For those interested in minimizing fore and aft movement while retaining some of the advantages of the cushioned arrangement, RRS offers a strut-retaining setup utilizing urethane bushings. These bushings are resistant to compression and expansion, yet still provide some of the noise and vibration dampening found in the factory configuration. With either upgrade, the result is a more stable frontend alignment, resulting in better vehicle control and handling.
Installing the RRS front strut-rod kit isn't difficult, but there are a few tips to make the installation easier. Let's look in on a spherical-end installation on a '66 Ranchero. Keep in mind that RRS offers a strut rod setup for Ford vehicles from '60-'73.