WD-40 isn't viscous enough to be used as a serious lubricant. Supposed to work OK to penetrate stuck pieces (note: LACK of viscosity) but IMHO better penetrating products are available. If you try to depend on any lightweight product as a lubricant (for anything other than sewing machines or model trains) you'll find neverending applications necessary. Even then you're probably experiencing excellerated wear. Is tempting due to easy propellant application, but spray greases are available. Best rule: if your grease gun will reach, use a proper lubricant.