To me, that sounds like the same issue as mine but with the added issue of not wanting to change down.... do the other gears change up and down fine? I think 4th, 2nd and Rev are all linked as are 5th, 3rd and 1st? Sorry, not in a position to confirm that but it is something to that affect. I think it would be interesting to see what codes you are receiving - so yes, having an ELM327 would be handy! (remember you need a laptop with Bluetooth for that to work properly).
I have a feeling that maybe you need to have your transmission bled in order to fix the changing issue however I think the crunching noise could be the same issue as mine which is a faulty 4th gear syncro.
Due to some unexpected BIG financial purchases I have had to make, I have not been able to have my issue fixed however my current symptoms (which is the further developed stage of your symptoms) is that it drives ok but I have to nurse 4th gear. Sometimes it grinds shifting up into 4th and sometimes down. If driving in 4th and de-accelerate slightly, it slips out of 4th and lands in 5th. A little bit annoying but still works and gets me round.
The solution is new gearbox if that's the case ($1400 installed by Ford with used gearbox). You must have the new transmission bled electronically by Ford if you replace transmission.
To answer your question, No there is no manual on these gearboxes hence why I am investing lots of time posting my limited knowledge and experience online for others to read. Its a pain in the ass actually but that's what we have to deal with
