Hard to shift in gears when is cold

[Slow325i]

Well here is story,when i got this 89 325i 5 speed i had to change tranny fluid because i didn't knowhow many miles had old one,so i did research what kinda oil tranny use http://www.bmwe30.net/cgi-bin/datacg...106&Section=11 and i find that i have 17mm INTERNAL wrench oil plug and i couldn't find labvel and i have to use GL-4 70W-80
When i poor old fluid out i find out that old oil is ATF (red oil like one automatics use) and i was thinkin that BMW dealer install this oil because every part i replace a few days ago was BMW part so dealer install right oil but since i have 17mm INTERNAL wrench oil plug i put GL-4 70W-80 and since than shifting is hard is hell
Right now in Erie , PA Northwest PA is 20F and in morning i have hard time to put in gear
So i was wandering do i have to use ATF oil or just keep using GL-4 70W-80 and broke shifter one day LOL