4.0 I do not know what tranny, 2002 explorer, the car was moveing and the light on the instrument panel flashed on and off, the car did not engage i would have felt it, it did this a couple of times, I did notice a few weeks back when I put the car in drive, it did not go right away, and then popped into gear, like the fluid was low, does the blinking light mean mabey the fluid is low, when the 4x4 light came on I was makeing a turn both times. I did replace my rad a few weeks ago and disconnected the batt, this is the first time this happened, never had any tranny trouble, never pused the 4x4 switch when this happened, I have used it before with no issues... never changed the 4x4 modual, were is that located? is that the problem or just low on fluid, (no leakes) car has 156K I have never changed tranny oil when I got it then it had 56K