A-833 OD gets stuck in second while driving

I had the very same problem on my OD. I very carefully adjusted the shift rods many times. But it never solved the problem. One day I finally removed the gearbox, rebuilt the shifter, and swapped out the side cover with the earlier steel ball-and-detent style mechanism side cover instead of the later "rooster comb" mechanism. If you do this you have to cut off the nubs at the end of the shift forks.

I'm sorry to say that I don't know which procedure solved my problem, but I am happy that I did both. Smooth shifting ever since.