2004 FORD Freestar Van will not shift.Will start and run But gear shift does not shift What could it be?

We have a 2004 Ford Freestar van. When we got it used last May. It had a Government Recall for the Torque converter. So we had that done it has not run right since. But 3 weeks ago my grandson and son we're driving it they said they heard alight pop and it coasted to a Stop and was just like you had taken it out of gear. Can any one tell me what it might be?

Based upon the info you gave I would first take a glance and see if a drive axle popped out. It really could be any number of things though.