I'm replacing the seals on a friends 2008 CRF250X and he supplied the parts, which only consisted of the seals, guide bushings, and slide bushings for the outer tubes. All of the other bushings appear to be in good shape (gray coating still in tact), except for the slide bushing located on the inner cartridge (#10 in parts fiche). The outside surface looks fine, but there is a band on center of the inside surface where it has worn through to the metal. How critical is this bushing and should it absolutely be replaced?