After my last track day/weekend I started experiencing a rear axle noise that sounded much like a brake pad dragging on the rotor. But it's not the brakes and it sounds like it coming from the differential. Perhaps it's the pinion bearing but I'm not familiar with the signs of failure here. The only change I made prior was adding a GT500 diff cover and changing out the fluid. I'm going to pull the cover, check for metal and change out the fluid. The car also has a 1-piece driveshaft and the rear is lowered about 1 1/2" but not sure if this would cause any excessive load/wear on the diff somehow. Opinions appreciated.