A few months ago, I had a 4-year-old bad battery on my '99 Camry, and was p lanning to take it to Costco for an exchange. I don't remember the details , but I might have had to jump-start the car at home before the trip.
During the trip I remember the shifting being really harsh, and made a ment al note to drain and change the transmission fluid, even though I had done so not so long ago.
Bought the battery at Costco (fyi: I think they are moving away from the pr o-rated 5-year warranty and replacing it with a 42-month warranty; you will get nothing after 42 months, but I do not remember the precise details), i nstalled it in the parking lot with my tools, and the shifting was a little strange at first driving home, but the next day, the shifting was smooth a s silk.
I'm guessing the battery didn't have enough energy to activate the solenoid s in the transmission, but that's just a guess.
I'm also not quite sure why the shifting was still a little strange immedia tely after changing the battery (removing the old battery should have clear ed any settings in computer memory, right?)
Anyway, this is just an FYI that some transmission issues might be solved b y simply replacing a bad battery, if it's over 3 years old.
Michael