This is for a 1990 Bronco Custom with a 302, manual locking hubs, manual 4x4, and an AOD. There was some heavy snow today in Indiana so I used 4wd and my way to school and then to work (about 8 miles at around 50 mph). After the roads were plowed I tried to get the transfer case to shift out of 4x4 into 4x2 with no success. It will shift into 4hi and low fine, but when switching from Neutral to 4Hi there is grinding. No matter what I do I am unable to get it to shift into 4x2. If i am unable to fix this by tomorrow morning would it be best to unlock the hubs? or does anyone have any ideas to get the transfer case to get into 2 wheel drive.