Need some advice. I have a 2004 Ranger, 4wd, 4.0, a/t, ext cab, 160k+ miles.
I changed fluid/filter and now it slips unless I start in low and shift manually.
Prior to that, it shifted fine through all 5 gears unless I'd nail it and then when it would hit like 3rd or 4th, it would go out of gear like missing a gear with a manual trans until I'd let off the pedal letting it catcvh up, then it'd go into gear.

Does this sound like something I can fix or do I need a new trans?

Thanks for any help.