If you have the plastic bushings then spraying them with WD40 was the worst thing you could do!

Clean them with de-natured alcohol and then give them a shot of a silicone lube or pull them apart, clean them and re-assemble using some petroleum jelly. Spray White grease will work also. WD40 will eat the plastic. It works "okay" until it dries but it attracts dirt and will act as an abrasive.