2000 Ranger transmission or torque converter

I was driving my truck and started to hear a grinding sound(tranny area to me) and pulled over to turn around and take it back home.. i didn't have reverse, or neutral. I drove it a quarter mile back to my house. on the way i heard grinding again and was loosing power. i made it home and parked it. went out the next day to check it out, it wouldn't move. it occasionally(once just enough to move it where i can have it towed, when i get to that point) moves in drive, but it wont move in reverse, and you cant hear it go into gear, but the tires try to move in drive, and reverse, but it wont move. the tranny fluid is normal, no burnt smell, and cant see any metal in it. the linkage appears to be moving, cant tell if driveline is moving or not.. ANY ADVICE WOULD HELP GREATLY.. its already had the transmission replaced in it once. (4 years ago)
Its a 2000 Ranger XLT, 4x4, V6 3.0 ltr fuel injected, (transmission is heavy duty for towing) automatic.