Just thought I would post my experience with a whine sound from my drive train. I had bought this 99 Ranger a couple of years ago and it had a whine sound coming from somewhere. Never having had a 4x4 before, I actually thought it was normal. I had heard similar whine sounds from other people's 4x4's before. Eventually decided it wasn't normal and was coming from the rear end. My mechanic looked in the differential and changed a couple parts. It was a little quieter but not much. Soon after we drove 140 miles to WV. the next day we drove another 85 miles to DC and returned 85 miles back to WV a day later. The following day we drove 10 miles to town and pulled up to a parking meter and the vehicle was immediately totally engulfed in smoke all around with a loud hissing sound coming from the right rear wheel (sorta looked and sounded like a real bad radiator leak would). A meter maid told us there was a repair place two blocks up the street. I called and they said bring it over. The thing was still capable of moving. I left it at the place and they ended up finding a whole used rear end assembly at a junk yard in PA, the whole thing, differential, axial and wheel hubs, everything. They did have to replace the brakes and rotors too and my total cost was $1200 and it totally fixed the whine sound. It has been over a year since it happened.

__________________
Gstewart
1999, 3.0L, step side, 4 speed AT, AC, 4wd, extended cab with those "suicide doors", redish orange ("Autumn Orange"), 176k miles, with heavy fiberglass cap and trailer hitch