'91 Transmission Problems

[Digital Dave]

I was wondering if anyone had any advice for these problems:

For one, sometimes, especially recently, in the first three minutes I'm driving my car, when I'm stopped, the idle will go up and down, never quite dying but getting damn close. After a few minutes it goes away.

For two, the RPMs on the highway at 70 are a little higher than normal - mine does about 2800, is that normal?

For three, a few times when I'm driving above 55, the trans will suddenly shift HARD out of overdrive, and won't go back until I stop and try again.

What's wrong with my transmission?

[raallison]

My 91 is doing somewhat the same thing. The first thing I noticed is that the idle at stop in drive higher. Engine is still running smooth. Now the transmission is shifting late. I noticed that after it is warmed up is when all the problems start. I opened up the transmission to change the fluid and filter. Sofar the inside of the transmission is clean.
-Rick-