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?

 

Not really. Make sure your power steering fluid is good and you may look closely at your wheel bearings.