I have a 2003 Excursion 6.0 Limited. I put it in low 4x4 to pull a friend out of some mud last night and now my transmision is stuck in low. It has the knob that you turn back and forth between 2wd, 4wd & low 4x4. The knob is back in the 2wd position but tranny is still in low 4x4. Is there any thing I can do to fix this or is my transmision broke?