My car makes the same noise, I've been tryin to figure it out also. When I changed my axels there were the 2 joints u have to knock loose with a pickle fork. I'm convinced its the top one which there's no fitting to grease it and they say my ball joints are fine. I have a bad rack, but I think its right where it connects to the wheel. I dont think it has to do with my rack but its the metal piece with the small rubber boot around top. I'm just trying to explain the best I can I don't know correct terms for everything sorry.