I've a clunking noise coming from the rear end everytime i shift gears. I checked the freeplay of the pinion and I noticed quite an excessive play while the parking brake is on and the tranny in neutral. The play is about little over a quarter when I turn the driveshaft in either direction. I wonder if this is normal for this type of rear end ? The car is a 2000 z28 6peed t56 and has 24 000mile and is virtually brand new and this has been like that since I bought it.