Cold Weather Transmission Startup Issue

I have a 2002 Buick Century and I have never had any problems with my transmission to date. I recently have encountered an issue when I start my car cold. When I put the car in gear, drive or reverse, you can feel the car try to engage into gear. After I release the brake to start moving the vehicle doesn't move. In order for the vehicle to move I have to accelerate, but when I do that it jerks violently. It's almost as if it's frozen. Granted I do live in Iowa and it's 5 degrees outside, but I have a hard time imagining that. Once the initial jerk is over, the car runs great. I've tried to let the car idle and warm up for about 10 minutes and that doesn't help at all. I talked to my local parts guy and he thought that my transmission fluid may be getting slushy?? I told him I didn't know when the last time my car had a transmission fluid/filter change because it was my wife's car that she inherited from her parents. I talked to a local repair man and he thought that the pump may be getting weak, but I dont know whether to believe him or not. I can't get the car in to be looked at for 3-4 days so I was hoping for some helpful advice. My father told me to drive the car on the highway for a bit to warm it up and park it in a warm garage and see if that helps. I might try that. One more thing to add. I did check my fluids after letting the car idle for about ten minutes and it was ok. I didn't notice any fluids leaking inside the engine compartment or on the ground. Before I drove the car a longer distance I backed up and went forward a few times to see if I could hear any strange noises and I could not.

Any advice you can give me would be much appreciated. I can recall experiencing a similar issue, back along time ago,when operating heavy equipment.....sometimes in extremely cold weather,when there was a little moisture in the soil......the tracks and tires of the equipment would freeze to the ground.....course, we were parked on wet dirt most of time... ....but it took a little shifting from forward to reverse and accelerating the throttle, to break them loose......this only happened rarely, when it got down in the teens, here in south georgia the tranny fluid could be low. to get a acurate reading the tranny has to be completely warmed up, which means after driving it about 15-20 miles. if u check it after just letting it idle, the level will read higher then it realy is cause the tranny aint warm enough.

if u verify the level is ok, id suggest getting a fluid and filter change and see if that helps. If you don't know when the trans was ever serviced, it probably wouldn't be a bad idea to have it serviced as Connie stated. When they drop the pan they can check for excessive clutch material or broken parts laying in the pan.

Could be a pressure problem when the fluid is cold. They would have to connect a pressure gauge up and see what the line pressure is at when the problem is occurring.Car Repair Talk's forum.