What's wrong? I have a 2000 Ford Ranger V6 3.0L engine--When the truck goes into overdrive, the O/D light flashes & when I push the button to go off & the speedometer doesn't even show the speed. When the speedometer shows starts showing the actual speed & the truck starts being in drive, then when I press the O/D button, the light goes out & it drives ok. Then, when I come to a stop, it will sometimes start out in overdrive & does as explained above, then when it kicks into the actual drive, the transmission clunks. Do you know what the problem could be?