Transver Case pops into neutral

[Vintage465]

We have a 2003 Dodge 2500 4x4 with a diesel and 6 speed. The transfer case unexpectedly popped into neutral while in accelerating, towing in 3rd gear, bringing the pickup to a halt real quick with a loud bang and crunch. We took the pickup for a drive without the trailer and it started up with the same clunking, and a whizzing type chattering, without poping into neutral. Pickup has 218,000 miles on it and has done very little 4x4 activity.

Thoughts?
V465

 

[Clb]

Bearings
Once you pull it apart it will reveal itself.
See if it has shift rail detent springs that are toast.