Mr Dean

Hi..just bought the missus a 1996 328i auto. All seems good but from cold the auto is a bit hairy. I think it is a sensor or cold start irregularity. What it does is slightly over rev from first to second ( and erratic ) and seems a bit clunky to engage. After it warms it is sweet as and changes really good. They reckon the trans fluid is for life but I might try changing. Any thought's?