nope its not that after all, just went out to have a look . Part 5 is a single piece unit ... and that mystery bit doesnt go anywhere in there and the clutch lifter is working fine as it is. It doesnt appear to be part of swing arm either. Its not part of the spindle collar as the outside diameter is too big to fit inside the swing arm bush and the inside diameter is too big for the spindle. Its not a swing arm bush either as the inside diamter is too small for the spindle collar to fit through it.