I'm wondering if a flush is really necessary or if I can just drain the old fluid and add the new somehow like an oil change? Where would you add the new fluid if you were to do this?

 

Its best to get all of the fluid out, seeing how its picky on exactly how much fluid is in there. For pressure purpposes

 

Umm... well not sure what you mean by drain vs flush, yeah it's possible to drop the pan and just change that if that's what you mean, but that's only about 7 qts of the 17 qts the whole system takes,so it's better to flush it all imo though. There's a nice write up by dirty who knows his stuff

https://dodgeforum.com/forum/3rd-gen...ion-flush.html

 

I was scared of the flush at the mileage I was at without ever having had it done, so I had a drain and fill done. But they pulled the pan and let it drain for a good long while to get as much out as possible. My old fluid still looked pretty good and I wasn't having any issues, and haven't had any since. The shop had to wait for the parts store to deliver a new filter anyway, so it had a lot of time to sit and drain.