I have an '07.5 Duramax with just over 13K and now have a second transfer case seal gone. This time the dealer said there is a sevice bulletin that calls for replacing the yoke on the driveline as well. anyone else had this done and how does it fix the problem of the seal failing?

I had mine replaced. They said it was a casting flaw and not letting the seal seat properly. Maybe its that cheap chinese crap in our trucks.