I had what I believe to be diff clunk on my previous car, an AUII XR6. I was unable to get it repaired. The dealer opened a PACE case on it with Ford, but we got nowhere. I have the problem a little in my manual XR6, but I don't know whether I am making allowances due to the previous ride or not. There are occasions when you get a 'jerk' and a couple of thumps, typically when slowing down or taking your foot of the accellerator. I also find myself on the clutch a lot earlier than normal in 1st, purely as this stops this problem at stop signs, lights etc. Is this what you guys are referring to?