So my 2004 taurus se recently failed on the highway. The tranny dropped into neutral and stayed there. Had to drive home in first only as it would shift into neutral instead of second. I replaced the shift solenoids which were going bad and cleaned out the valve body and it still has the same problem. At 340,000 miles I was thinking that one of the bands snapped or something else bad. Should i rebuild the tranny, get a new one, or sell the car?