Anyone ever have to adjust it?

I still haven't figured out why my 4hi pops out after a few minutes. I know it's engaged because while testing I can feel it binding up in the front end. My service book isn't too helpful, it's a 1/2 page that just says to disconnect the linkage and drill a new hole where the linkage matches up with the bolt hole? No diagnosis or any other things to look for?

4lo works and stays locked in until I pull back to 2hi. I can pull and hold the stick it in 4hi and it'll stay engaged. No grinding or noise of any sort, I just see the light go off and reach down finding the stick back in 2hi.

I've searched the site here for the past 2 days reading hundreds and hundreds of posts discussing similar complaints, but no one ever came back to say what they found as the cause.