Report I Hope I Don't Need A New Transmission in Engine & Drivetrain Posted January 15, 2015 1998 mercury sable wagon. Duratec engine with the AX4N trans. Won't shift into OD. In busy stop/go traffic after driving for 20-30 mins the OD flashes continually. When I stop he car and restart the engine the OD light is off until I drive again in busy stop/go traffic. If the vehicle gets to an Interstate before the OD light starts flashing the light typically doesn't come on. Any thoughts?