4L80E doesn't shift into OD when cold.

[Crookedaxle]

My 1993 K2500 with 7.4l and 4L80E doesn't want to shift into OD when it's colder out. In the summer it's rarely an issue but as soon as the weather starts getting cold it doesn't want to shift into OD. I usually have to drive it a few miles and then turn it off. I usually just restart it going down the road if there's no traffic. After I restart and take off it usually shifts. It seems to be more of an issue with the tranny getting warm rather than the engine. I can let the engine warm up for 10-15 minutes before taking off and it doesn't help. It hasn't gotten any better or worse in the 25,000+ miles I've put on the vehicle. Performs fine other than this issue. Any ideas where to start looking?

 

[bowtie-72]

Did you try dropping the trans. pan and changing the fluid and filter? You can have a look at the inside of the pan. I know it`s a pita to drop the crossmember to get the pan out, but it is worth doing. If you haven`t done it yet it needs to be done anyway. That`s where I would start.