I have a 99 F350 with 178,000 on it. My OD light has been flashing on and off for over a year. Ford found nothing and didn't fix it either. For the last few months on top of the OD light flashing intermittently the transmission is slow to shift from a dead stop. Both happen at the same time. The local reparable transmission shop diagnosed the front clutches in the transmission slipping. Total complete rebuild dead or alive is $2300. I'm still driving it since I have had this problem for some time.