missed gear

when im driving my 64 cj5 accross the field i have to downshift from 3rd to 2nd. when i go out of 3rd and into 2nd it doesnt go in,no grinding or buzzing it just acts like its in nuetral. its not a common problem it just happens sometimes is their a problem with the trany or just driver error/technique

 

My 2nd gear was "missing" for a while last winter. I assumed a shift fork was somehow binding. It was too cold to work on it so I put it off until spring. Months later, I did a routine trans top-off in gear oil and 2nd gear mysteriously came back a few days later!!!. It has been fine since and I never cracked it open to fix it. Go figure!

I also have a 1st and 2nd "pop-out" condition under load so that may be contributing. I keep it topped off and it keeps on truckin!!