I have a 2002 S60 AWD with 61K miles on it. The Volvo service manual that came with the car says that at 60K you need to service the AOC AWD coupling by changing the oil, filter, and replacing the O-ring. 2 separate Volvo dealers with "Volvo certified" mechanics have now told me that they don't have a clue what Volvo means by this in the service manual. I am not looking to spend any more money than I have to, so I am quite happy not to have this AOC AWD coupling serviced, but if it is something that truly needs service I don't want to ignore it. I have to admit my Google searches on this topic have been sparse in providing concrete answers to show to the mechanics .....so I am hoping someone here can tell me if this is a real service item for the S60 AWD, or just a misprint in the manual. Thanks!