swivel seal has gone, this then usually leads to a new swivel ball, wheel bearing, more cash, oh look my calliper is a little seized, more cash, hey my ventilated disc is a bit rusty, more cash, until you have replaced everything to do with the drive line, suspension and steering. Oh wait, was the radiator looking a little corroded down the bottom? More cash. Or just get some one shot grease and pop it in the top plug on the hub and look at nothing else whilst your under there.