If it doesn't have a zerk fitting it's a sealed unit. The manufacturers calls it " good for life" whatever the heck that means since they don't last the lifetime of the vehicle. I've known of people installing their own zerk fittings on these sealed units by drilling, tapping and screwing in the fitting however, I don't know how efficient the results are unless you unload the balljoint to get the grease around the socket to properly disperse the lubrication.