My 1997 Tahoe 4 wheel drive will not shift to 3rd

What is your question?

Changed shifter silinoids still does the same won't shift until 3500 RPM let off it shifts..i changed the fluid and the filter also...what started this I was pulling a trailer 20 ft box...the transmishion started slipping I got out and it blew the fluid out of a black hose...i put fluid back in it and it was ok but then the next day it started doing again

How long has your 1997 Chevrolet Tahoe had this problem?

Been setting for a year