First time on this site so please be nice !!!

Ok it's got 204+ miles and is the 5.2V8.. The tranny has been acting alittle wierd since I bought it a couple months ago. Goes into R/!st with no issues, shifts somtimes kinda wierd when on the gas (somewhat) 1-2 in-out searching but not all the time? And when it shifts from 3-4/od somtimes I get a shudder then it goes in. I have no idea when this was last serviced ? by the PO. So I looked up alittle online and got a manual and wanted to flush--(Change oil-filter-adjust bands) well I changed the filter/oil (Didn't smell burnt or have any major chunks/metal in pan ) and TRIED to adjust the (low-reverse band) boy I should have left well enough alone.

Now after all thats done it seems to shift better everywhere else but when you put it in drive (First) again not all the time it starts to rev then engages... BAD I know... Anyway I'm about ready to have a shop do it right or maybe give it one more try before I really screw it up. Iv'e heard of various differnt specs and can't find my M/N on the tranny..