My car has developed a "whine" or "humming" noise. The noise only happens between 45mph up to 65mph. It goes away after 65mph. The noise will occur in both 4th and 5th gear. It doesn't matter which of these gears I'm in. It's like a low "whine" or "hum". I had gear installed about 4500 miles ago. I also had the tranny tsb done about 8000 miles ago. Mike(svttech) I know the tranny was rebuilt with new synchro's, could this be the cause? I don't know if it's the rearend,tranny or u-joints. Thanks guys. Pearl02.