89 S10 transmission problem

I have an 89 S10 and it has been getting hard to put it in 5th gear. It just grinds when you try. Sometimes it clunks in and stays, but sometimes it pops out while driving. This is the only gear it does this in. Every other gear is just fine. It does ok sometimes going in when you get over 50mph. Is this common and should I consider a fix or replace? I have another with a shot 3 to 4 fork. Could it be a donor or is it worth the trouble and money?

They can be repaired but parts are expensive for them.
Swaping used parts from one to another does not work out very good.
If you are going to fix it get all new parts for one or the other.
Some transmission parts places have rebuild kits.
Good luck.
MT