If you have 1 wheel jacked up with the locker on and hubs locked you can rock the front wheel with a fare bit of effort and it almost seems to jump a tooth or spline.
It does it with either side jacked up. When it does release it will turn the pinion so it clears either CV or hubs from being broken.
The strange part is you have to turn the drivers side in reverse and the passengers side forwards to do it
Dosen't make any noise while driving. Only found out it wasn't working trying to go up a hill last weekend after it was working earlier in the day.
There is air getting down to the diff.