I was plowing this winter and noticed the AWD was not kicking in when I switched to reverse until I would let off the throttle and hit it again. I know the issues with the roller cages cracking... but this was just a little different... So I took the Front Differential out and opened it up.... Everything looked fine... nothing worn, cracked or missing anywhere...
Was going to just change the fluid again but decided to just take the diff to the local service guy and let him have a look... He ohm tested it and said it was good.... He did ask if the PLATE-ARMATURE P/N 3234407 had normal wear bands... in which it looked just like the service manual stated. Curious about the curved armature plate that I had seen when I took mine apart, I asked him to see a new one... and glad I did. The armature plate is supposed to be flat and mine was curved... First one any of the service guys have seen...
Replaced the armature and everything is back to normal... Hope this helps someone out...

 

Thanks for taking the time to give everyone a heads up.