Thanks for your comments it does help as I try to get everyone input.

I'm planning on doing a detailed procedure for troubleshooting the AWD when done. Lots of great info but just not in one place!

No real sounds when losing awd. Some report a thunk but in my experience it would grip sometimes but not others. Then finally one day I had nothing. I think it is very possible that the sleeve could grip on an unloaded car and then not have enough teeth left to grab when the vehicle is actually slipping. I would start by scanning the car for codes and if nothing comes up for the Haldex system then it is most likely the sleeve!

Hope this helps!