Most OEM U-joints today are pre-lubed and cannot be lubricated without disassembly. They are great u-joints and are good for people that don't like to take the time to lubricate their driveshaft properly. If you have u-joints that need to be lubricated make sure you use a good quality, lithium, soap base, extreme pressure, grease that meets the N.L.G.I. grade 2 specification.