I can hear this in the whenever theres a shift in force from pressing and letting off on the throttle. I've owned a few other fc's and never heard anything from inside those. My friend who currently has my car thinks its the bearings in the diff. I had the side bearings in there replaced recently when the OS Giken 1.5 way diff was installed. SAME NOISE WAS THERE BEFORE THE DIFF INSTALL. Here's a video.


What do you guys think?