I had a local shop install a new used posi series 3 carrier in my 9 bolt rearend and good used 3:27 gears. We rebuilt the entire rearend with new bearings etc and upon driving the car whenever decelerating or letting off the gas I get a loud whine. I dont think it is the used gears being the problem but the shop says it might be the old wear pattern. The noise is very loud when coasting to a stop and i think it is a simple setup mistake. From what I can tell you cant even buy new gears in this ratio and these gears I put in looked in nice shape. I am not going to drive it and probably will bring it back but it is irritating the we have to open up the rearend and half to go through the entire process again. We might have to do this multiple times to eliminate the noise right?