I have a 98 Mountaineer/automatic/AWD that will not engage the wheels when the shifter is engaged into forward or reverse gears. It gave me no warning i.E. Occasionally refusing to go in gear or grinding sounds, etc. It just quit moving without any warning. It makes grinding soulnds when I try to put the shifter back into Park position after attempting to shift into Forward or Reverse gears. I am thinking that it must be a problem inside the transfer case, since there is absolutely no movement of the vehicle in any gear position. Thanks in advance for any advice on what the problem might be.