Wednesday morning I was driving from Fort Mohave, AZ to Kingman, AZ. A distance of about 40 miles with an elevation change of from 500ft to 3700ft. As I was starting down the summit into Kingman my truck made a very loud screeching noise for about 30 seconds and the truck lost all power to the wheels. The engine still runs fine. I coasted into a parking lot next to a gas station and when I went to put the truck in park the transmission sounded like it was grinding gears, but there was no drive in any gears forward or revers. So what do you think, is it the transmission or the transfer case? Oh, bye the way the transmission was last rebuilt in 2004 and the truck has about 175000 miles total.