How to Correct Bumpsteer

11 Securely tighten the large cap screw, which snugs the spindle and spacer block together. A large Allen wrench and closed-end wrench work for now, but this nut and bolt need to be torqued to spec with a torque wrench, which we'll do later.

12 We're ready to install the stirrup clamp, which fits right over the spindle arm and down onto the spacer block. Set it into place as shown here ...

13 ... and install the supplied bolt, washers, and nut. As with the tie-rod stud, the spindle arm may need trimmed to allow the clamp to fit completely over the arm. We didn't have to in our case, but if you do, grind or file the spindle arm to obtain the proper fit.

14 If trimming is required, the strap should be centered evenly around the spindle arm as shown. Tighten the strap nut and bolt securely with wrenches, then use a torque wrench to final tighten them to 40 lbs-ft. Next, install the set screw and accompanying jam nut that help hold the stirrup clamp in place. Securely tighten the set screw as shown here, then secure the jam nut in place once the set screw is tight.

15 As mentioned in step 11, the main cap screw that keeps the spacer block attached to the spindle arm needs to be torqued to spec with a torque wrench. On '65-'69 cars with 7/16-inch bolts, torque the nut to 75 lbs-ft; on '70-'73s with 1/2-inch bolts, go to 100 lbs-ft.

16 Install and tighten the jam nut after the nut below it is torqued to 75 or 100 lbs-ft. The jam nut should be torqued to 30 lbs-ft.

17 Here's the installed spacer block, stirrup strap, and all related hardware. Note the sufficient clearance between the tie-rod stud and the bottom of the steering arm after trimming the stud, as well as adequate room for the cotter pin to fit underneath the spindle arm.

18 In short, the spacer block "lowers" the tie-rod end so it's more in line with the lower control arm. Looking here, the angle of the tie rod and lower control arm are almost identical, thus eliminating bumpsteer. Bumpsteer can vary from one car to another and our car was the worst we've ever experienced. Now it's as good or better than any other vintage Mustangs we've driven.