I recently purchased a 2004 XC90 T6 AWD with 82k miles on it. I took it to the dealer to catch up on any "deferred" maintenance.

One suspension component replacement required the front axles to be removed. Once removed, they called and said a plug had cracked in the axle allowing grease into the transmission. They also assured me that there had been very little leakage at that point and that a new axle and a transmission flush would put everything right.

I've been edgy because of an occasional hard jolt when accelerating from a stand still. The dealer found the transmission was a bit low on fluid. They also made other adjustments and so far so good. That work and a window regulator rivet replacement (wicked door rattle) cost $5.18. Highlight of my day.

After reading this thread I feel like I've dodged a bullet with the transmission failure. At least I hope I have.