1998 Dodge Carvan Transmission Problem

I have a 4 cyl with 3 speed auto tranny. It has been rebuilt 40,000 miles ago. Recently when it is cold out 50 degrees and below, when the van is started, It will not go into 1st. When it warms up after a minute. I can take off but it will not shift into 2nd until the engine warms up a bit more while driving. I won't have drive until I drive about a mile. When it shifts into 3rd, it slips for a second. Now that we had a few days at 75-77 degrees. the tranny works ok right from start-up but, going into 3rd(drive) it still slips a bit. Would a just a tranny oil change help, using ATF+3 fluid? Or? I don't have the funds to get a rebuild done, again. My last Dodge Caravan had to have it's tranny rebuild twice, it was a 4 speed auto. Now I find out that Dodge had terrible 4 speed trannies.....Won't buy a Dodge again. Anyone now a reputable tranny repair shop in Dallas, kennesaw or Marrietta, Georgia?

Most tranny problems in the Caravan are caused by taking your van to service place, and they use Dextron fluid. You can use ATF+4 they say, others say it's not good for your seals. ATF +4 is full synthetic, so it should last longer. I have found that ATF +3 is hard to find, but still available. I used ATF +4 in my old leaky trans and it seems to work good.