Well, my son thought it might be an axle. I am really not sure. I started hearing a rattling about 1 1/2 months ago. I noticed at that time that the panel inside the wheel well was loose so my friend secured it for me and when I drove the car again the noise was still there. It sounds as though there is a tool banging around but we could not find anything and it only does it on bumps, uneven roads or driving into a driveway. I have not noticed any vibrating or a change in steering. That annoying noise is all. We did however notice that the engine kind of jumps when you put on the brake, shift into drive and rev the engine. I recently had the catalytic converter changed but I hear the noise in the front right side of the car while driving.