2005 XC70 rear diff leak.

[ardbeglily]

I wondered how common it is for the rear diff to leak on the XC70. I had a rear diff leak repaired at 82,800 miles with an o-ring, drive shaft seal and chemical gasket. The rear diff leaked again at 104,668 miles. Is the leak common at 82k and should the repair last more than 22k miles? Thank you.