Ford Repair: 2000 Ford Explorer XLT 4x4 Transmission, metal shavings, input shaft

Question
I realize that this may be an overly general question, but here it goes...

I just purchased a 2000 Ford Explorer XLT in 'as is' condition with what was described as a "bad transmission". The vehicle does not go into gear at all in any gear. I have never encountered a bad transmission that didn't go into any gear so I suspect it may be related to the 4WD system. The engine sounds great and the vehicle is in otherwise fantastic condition. I figured the cost of a transmission rebuild into my purchase price but I am still hoping that a complete rebuild may be avoidable. Any ideas on where to begin and what this problem may be? Transfer Case? Worst cae and best case scenarios? Thank you for your help.

Answer
Joseph-

  If the vehicle doesn't go into any gear at all, I would first suspect the torque converter.  Think of it like a clutch in a manual trasmission, except it uses hydraulic pressure to move the gears rather than direct friction.  If he converter itself has given up or if some of the spline on the input shaft are chipped or broken, the car will most likely not move.  This is a fairly easy fix so long as any possible metal shavings haven't evtered the transmission.  If that were the case then you'd really need a total overhaul.  Hope this helps.

Steve