New to this group. Looking for help to answer a long time problem. Between 95 KmH and 105 Kmh a low frequency vibration occurs that is worsened by slight accelleration and even more evident after 2-3 hrs summer hot highway drive. Shifting to neutral doesn't change anything, nor does turning right or left. Dealer has been trying to fix since March 2002 to no avail. He has replaced CV joint, driveshaft, bevel gears. What is strange to me is that one of the dealer's first 'fixes' was to put synthetic ATF at around 50,000 Km. This made rumble less noticeable but still there. During 96000K service last week, however, they inadvertantly put back Dextron ATF and the vibration is much more noticeable again. I will go back to the dealer with this but before I do; does anyone know if Volvo have had any unacknowledged tranny problems along these lines? I have an extended warranty on this car but it's difficult to get them pinned down when a major repair like tranny replacement might be necessary. Any help or comments appreciated.