A while back someone posted about having a ~"metal grinding" sound from the rear of the car. (The sound was obvious while making low speed turns in parking lots.)
Originally when I heard this on my car, I replaced my questionable rear wheel bearings hoping that noise would vanish. Nope, still there... Finally after seeing a Usenet post it clicked.
It seems like the noise is coming from the LSD--specifically the clutch plates slipping inside the differential due to lack of proper friction/lubrication...
It started for me after the dealer replaced my differential fluid a while back. I'm thinking for the following possibilities:
A) Wrong fluid was placed in the diff.
B) Old fluid was very old and the sludge was masking the sound.
I'm going to try replacing the fluid with redline's gear oil hoping that the viscosity and friction co-eff will solve the problem. If not though what are my options? New Diff? Can I rebuild it?