Loosen the old screw locknut. Remove old screw (there is room). Insert new (gold) screw and tighten until it just makes contact with the rack. Start engine and tighten until the rock just stops - tighten too much and cold starting problems may result. If the rocking returns when the engine is hot, you may have to adjust the screw when the engine IS hot.

The rack damper screw only damps the rock caused by the natural resonance of the rack and the linkage, it will not cure roughness caused by anything else!

Marshall