WD-40 is technically a solvent and water displacer, not a long-lasting lube. It usually just flushes out any remaining grease or lube making things worse than they were in a day or two once the WD-40 finishes evaporating as it does. I'd leave the WD-40 in the garage and start using a good lubricant instead, like a spray lithium grease that you can spray into and work down into the hinge mechanism.