Transfer Case/Transmission Grinding
 

My transfer case or transmission is grinding in my 94 F-250 5.8 manual. It isn't the front axle (Dana 50). The driveshafts do not have significant play.

It grinds in 2 wheel and 4 wheel while under moderate to heavy load. The grinding is getting worse requiring less and less load and time goes by. It sounds like fine gears grinding. As soon as it's not under significant load it stops. There is no grind when decelerating or under very light load.

Should I go ahead and drop the transfer case? Could this be a problem with the manual transmission?

There is a different dull noise every now and then. Someone said it is the throw out bearing. I don't know if this would have any affect on the grinding.