Binding issues

[trap121]

Does anyone's rear diff make a weird clicking noise when you spin the wheels?

My esc keeps jumping up to 160-170 after 10 minutes on the track. I have dropped pinions and raised pinions and it is still the same result...hot esc, cool motor. I rebuilt the read diff and I still have the noise.

I think something back there is binding and causing the esc to overheat. I cant figure out what it is.

Any suggestions??