2009 160k miles transmission is jumpy

Hi all. First Time posting.

I have a 2009 Limited 4x4 with about 160k miles on it. Over the past few years, I've had an issue where the transmission seems to slip or jump on the downshift. This happens especially with the cruise control on. There are no service engine codes coming up. Although one time I was in cruise control and on a steep hill, the transmission tried to downshift and almost seemed to slam and the vehicle went into "limp mode". I pulled over.. turned it off. Started it back up and everything was fine. I just avoid cruise control almost altogether now, unless things are really flat. I also have to avoid stomping on it or she seems to hesitate and stutter, so I try not to push it.

When I took it into the dealer about 2 years ago, they noticed it was a little low on transmission fluid, so they topped that off. 2020, I barely drove so not it didn't need much attention last year. But as things open up, we are wanting to take more road trips.

Any thoughts on what should be done? I love my truck so I'm not ready to give up on her yet, but I'm nervous about what the future holds.

When was the last time the transmission fluid was changed?

I'll be honest. I haven't been the best caretaker! I do not think the transmission fluid has ever been changed. Do you recommend?

Absolutely. Always start with the cheap and easy stuff. Fluid changes are basic maintenance and transmission fluid does break down over time/miles. It's definitely worth doing even if it doesn't resolve the issue.

Some will say changing old fluid on an old transmission will cause a failure but the reality is it won't harm a healthy transmission. If it fails after a fluid change then it was on its way out anyway.