WD40 is a very thin "penetrating" compound, designed to briefly lubricate and assist removal of stuck nuts & bolts. It is not a long term lubricant. You really should use an automotive grease on the joints. This will remain there for several years. Either silicone based, standard or lithium based will do fine, and you only need a very small quantity. Don't want it dripping onto the carpet do we!
Richard, Nottingham, November 2008
