Fix the “clunk” with your S197 Mustang upper control arm. You can do it now by ordering our new upper control arm step bushings. Ford designed a fantastic rear suspension when they came out with the new 3-link rear suspension. The only problem is when they made the upper control arm mount they decided to use a 14mm bolt and with a 16mm mounting hole. This 2mm difference is size creates slop in the mounting area allowing the control arms to move in the mount which can create a clunk sound. We come up with a fix for this oversight and designed special reducer bushings using very high strength 1144 stressproof steel which is stress relieved and heat treated for superior strength. These bushings reduce the hole size from 16mm down to 14mm and work with any control arm which uses the factory upper control arm mount or aftermarket mounts using the same 16mm hole size. Using these reducer bushings will eliminate the common clunk especially when using aftermarket control arms. These spacers are included with all of our upper control arms so there is no need to purchase them if you are ordering one of our upper control arms.