I have a 1980 240D sedan with an automatic transmission. When I start the car and drive it first thing in the morning, the transmission shift from first to second gear is rough, it snaps my head when it shifts! However, once I have been driving it for about 15- 20 minutes and it's warmed up, the shifting from first to second is much smoother and about the same for the other gears. Is my transmission having a problem, or is this typical for a car of this age?