Fixing the bumpsteer

I've driven the car several times on the road, and it is very unstable. When I accelerate, the front rises and stays up, conversely when decelerating. It is my understand this is due to bump steer. Bump steer is an unwanted changing of toe (where the tire is pointed) when the suspension moves up or down. Ideally, you want zero bumpsteer, where the toe remains unchanged.

All old mustangs have some bumpsteer. Some have more than others, especially when changing the spindle, specifically to a 67-69 mustang or Granada spindle for disc brakes. These spindles raise the outer tie rod mounting height by 0.8" causing severe bumpsteer IF accompanied by a lowering of the upper control arm - which I did - bummer.

To fix this problem, I purchased the Baer bumpsteer kit which allows you to lower the outer tie rod height selectivly by shims. Unfortunately, their tie rod sleeve did not match with Randall's Rack, so I exchanged it for a different one from Baer. However, it is not reverse threaded, so changing toe is a real pain!

Anyway, to check bumpsteer, one must remove the coil springs and shocks. Then get a control height of the car at normal ride height. This was done my measuring the Lower Control Arm height above ground. Then, attach a $10 lazer level from Home Depot to the front tire aiming at a flat sheet paper and mark toe throughout the suspension changes.


My rudementary bumpsteer gauge showed mixed results. I reduced bumpsteer significantly during compression, but hardly at all at rebound. Hmm. Anyway, I took the car for a spin, and it made a HUGE difference!! The car actually drives straight now.