I have changed the fluid and filter and the weather has warmed up and I no longer have the harsh downshift at stop signs. I have no idea why that problem has gone away. Maybe because of the fluid filter change maybe not. After the fluid change the problem did seem to get better as days went by, but then again it is warmer out now too. One problem that I still have is that when coasting above 30 mph the tach will have sudden drops, sometimes all the way to zero and then back up to where it should be. At times when it drops as low as zero it does not recover and the engine stalls. This will not happen at all if I coast in neutral. Also when I see those big swings I cannot feel the car slowing down or speeding up at all. Pretty sure this is a transmission problem probably related to the pressure control solenoid. Any Ideas?

Unless I missed something in the thread, the tach issue could be crank position sensor related.