Movement of the suspension pieces, especially when encountering sharp bumps or potholes, is not only vertical but also horizontal. IMHO, when the bump or pothole is encountered, the suspension deflects horizontally against the bushings (LCA, UCA, & strut rod) as well as vertically against the TB and shock. This horizontal deflection is what causes the bushing to get loose compounded by the natural deterioration of the rubber of polygraphite. It seems to me that this is supported by the anecdotal information provided by other posters about the premature wear of bushings in cold, roughly paved environs.
