Need help with diagnosis

[Ron_85BJ60]

The last snow storm when I engaged 4-wheel high ( push button) there was a nasty scraping crunching kind of sound. There was considerable vibration at speeds over 40 MPH or so. I did not leave it engaged for long and have tried several times since with the same result. How bad am I screwed?
Thanks,
Ron

 

[Waggoner5]

Possibly just a hub not engaging.

 

[zebrabeefj40]

...or one of those busted birfield thingies. Or it's not making it all the way into 4WD, the crunching grinding noise being it trying to get there. Might help to have someone else tool around a parking lot while you listen from the outside to see where the noise is coming from. Or get someone to drive while you listen with your head out the window.

Nick