I have no idea what's normal in terms of rear differential "play" but I've noticed lately that in 1st and 2nd gear when I roll on and off the throttle there's a clunk coming from the back end. I just jacked up the car and with the rear end in the air if I turn the wheels clockwise and counter clockwise there's a few degrees of play before it feels like anything in the rear end connects. It's an annoying noise and at first I thought it was the transmission, but after turning the wheels it's definitely the differential, ring, pinion, etc.
What's the most likely culprit? BTW, I beat the utter shit out of my car so nothing surprises me, would just rather know what I'm looking for.
Scott