I have an '07 Jeep Commander (all wheel drive). Coming home, I went across railroad tracks and lost all my gears. No park, no gears. The transmission fluid is full.
My mechanic says it's a bad transmission, but the Jeep dealer says it could be the torque converter. However, inside where the linkage locks it in park and engages gears there's no sound -- feels broken to me. (Note that when I got the car back from the mechanic, he said he did check it out, but there's no sign of the transmission pan being off, so he may or may not have.)
There's no resistance at all switching the gear lever from park to low. I can't hear it do anything inside transmission (before you could hear it click into gear). I've gotten under it and let my son-in-law move it back and forth -- no sound, no resistance. The shifter moves but no sound.