tranny not shifting to second

[hummer_maxxer]

so heres the story, yesterday we were burning off some old tires and didnt notice to tranny temp til it hit about 200. after letting it cool back to about 150 i went for a ride and now it doesnt wanna shift into second while on the gas. it works fine when the tranny is cold tho. today i drained all the fluid and changed it along with the filter and still the same things. is my tranny screwed ???

[Orange7.3]

bump.....bump