Any of the Dodge trucks I've owned with an OD trans will not shift into OD when it's cold. I've had a 90,95,96 all do this, even my 05 does it. My brothers 96 and my dads 98 do it as well. And by cold I mean -25C (which is about -13F) and I haven't let it warm up at all (yes I know that's not good for a vehicle but sometimes you have no choice)