I'm in the process of replacing the speed sensors now from a hard shifting transmission. I had this problem before and it just went away. Anyways, I know there a two sensors that I need to replace: one on tranny midway on drivers side and one on tranfer case (4x4). I did notice that I had another one at the rear of the tranny, not plugged in, and no wires for it. My thoughts are that this is for a 2x4 model and not needed for a 4x4 model, therfor not connected. Is this correct (I hope)?

Thats right.:)