Ok dude first gotta say I loved the camera rig I actually laughed out loud but hey it functioned right.
Second, bad news I still couldn't see anything the second video is definitely better than the first and in the general area. Have you been under there when someone else tries to recreate the noise?
I really wish there was more to see or more that could be seen with the rig it really was a note worthy effort. Maybe someone else has ideas? I do think that it looked odd in the way that I couldn't tell if I was looking at item 3 or item 11 from the parts graphic, in your video. If it was indeed item 3 it is either on the wrong side of the dust boot or the boot is damaged (item 6). If it was item 11 I didn't see anything around it much, sorry.