The sleeve K 27406 is a precision-fit bushing designed to support spindle K 27401 in the Sulzer ZV40/48 starting/valve assembly. Acting as a replaceable wear surface, the sleeve maintains correct radial clearance, reduces friction and prevents direct metal-to-metal contact between spindle and housing. Made from a wear- and corrosion-resistant material, it simplifies repairs (the sleeve is cheaper to replace than the housing) and helps preserve alignment and smooth operation — inspect for scoring or ovality during routine maintenance to avoid sticky or misaligned spindles.