So the wife Explorer is shifting funny, when you take off it will go from 1st to 2nd and then when it should hit 3rd it will go back to 1st. If you then let off the gas for a second or two it will then shift into overdrive. The shifter will only work for 1st, if you take off in 1st, shifting it to 2nd does nothing. Also when at speed you can't turn overdrive off, the light will come on but it don't down shift. So I am thinking 3rd is not working at all. There is no slipping or anything else wrong.

I am not a big tranny guy so any help would be great.