I have a '98 S70 T5 w/5 spd manual trans. It is making a churning sound very similar to the one made by my Dodge van (w/rear wheel drive) when it had a bad differential. It's most noticeable when cruising at sustained speeds. Lower gears and slower speeds really bring it out. I took it into a shop and they said that they could hear it when it was on the hoist and that the differential is integrated into the transmission. So, the only way I could fix it is to replace the transmission. All other front end components appeared good. Before I even entertain that step, I want to verify that this is truly the case. Is the differential integrated into the transmission? Also, if I shift quickly, there is a little clunking sound like metal on metal when I let out the clutch, coming from up front. I can sort of feel it through the clutch pedal. This all points to the differential. Any ideas?