I posted in the XC forum as well but curious if other v70 owners had expeirenced this:

Bought the car 3 weeks ago drove back from PA with this weird noise, I thought it was the heater core gurgling. the noise bothered me enough to take to a volvo tech (not dealer) I took him for a quick ride and he says, yep exactly what I thought it might be you hear the noise under load that's your transfer case its gone/going bad. His remedy pull it out make it a 2wd xc (not paying the bigger cost to retain the AWD functionality). So my questions are these has anyone else had this done to their car? What type of fuel mileage did you get once done? Any bad things come from doing this?

Thanks!