2005 XC 90 2.5T Roar from Transmission

[toxtreme]

So I have a 2005 XC 90 2.5T that has around 150,000 miles on it, I hear a roar sound only when decelerating and was wondering if others have had this problem and what it may be? It was AWD but the drive shaft was squealing around 100,000 and the dealer said as long as I didn't mind it being FWD he'd remove the drive shaft to the rear wheels and save me $1600.00 so I went with it, now just FWD, anyways just wondering if anyone else has had this issue and is it a big problem. Besides the normal stuff that needs to be replaced on these cars it has been a good vehicle. Please help if you can, the wife is on me about this, it's her car, if you get my drift!!!! Thanks