Auto transmission woes

First thing in the morning, my 95' doesn't like the shift from park into reverse. It slams or makes a violent "bam" when I shift it into reverse. Its ok, if I go straight into drive. However, I need to get off the driveway. Once car is warmed up, shift to reverse is smooth. Any ideas or suggestions? I'm taking car in for tranny fluid change so hopefully that will help.