Cold weather problems

[MPittman]

I have a 1997 Ram 2500 with 180,00 miles and a 47RE transmission. Trans is fine until the outdoor temp is around freezing or below, then it sometimes slips a little when I innitially shift into drive. It shifts fine after that. This has happened for the past two winters. I figured I was due for a new ( and beefed up) trans but before plunking down the money I wanted to see if anybody had any ideas. Also, when I initially start the engine and turn the heat on to defrost in the winter or turn the AC on in the summer and then shift into drive the engine occasionally stalls out. Didn't think this was related to the trans problem but vaguely remember hearing sommething once about a sensor on the trans that effects the compressor. I appreciate any input. Thanks!