A/T late shift when cold, cold transmission = late shift to fourth gear Options

[silvercelica97]

couldn't find much on automatic transmissions, but i thought i'd give it a go.

I have a 97 Celica ST with an automatic transmission ~150,000 miles on it. When the temp drops below 60 F it hesitates to shift to fourth gear and will rev up over 4000 rpms before it shifts. This only happens before the car warms up, all subsequent shifts are fine. I now warm up the car for a few minutes before driving it, and it solves the problem.

Should I change the transmission fluid? To my knowledge it's never been changed, but I've heard differing opinions on this. Some say to change it and some say it will do more harm then good since it's old/high miles.

What should I do?

I don't know much about cars...just a girl

thanks