Im not exactly sure. Its a guy I work with so I can ask him but right now he has major health issues so he hasn't been in and I didn't want to bother him with it. He seems to think its the passenger side axle shaft because he said it didnt do it right after the lowering but hes not sure. I do know that it felt worse when I would take a right turn but I don't want to start replacing parts that don't need to be replaced.