There is no 6 cylinder S60? They only come in 5 cylinder asperated engines or 5 cylinder turbo engines. As for the loss of your all wheel drive on this thing. What I would do is remove the bevel gear (transfer case) and on the transmission sleeve where the bevel gear slides into inspect the teeth. More then likely the teeth have all stripped away. Also inspect the bevel gear teath as well for any damage. You can replace the sleeve on the transmission but will need a special tool to pull it out. NOTE: IF YOU DO REMOVE THIS SLEEVE REPLACE THE SEALS AS WELL. VOLVO MAY SELL THE REPAIR KIT WHERE SLEEVE AND SEALS COME AS A KIT OR YOU MAY END UP BUYING EACH ONE SEPARATE. To install new sleeve just use a rubber mallet and bang it in. Good Luck.