Wheelhorse tractor popping out of second gear

[Froglee69]

We have a 199? 14hp single cylinder Manual trans. We have converted it into a pulling tractor for our grandkids.
It pops out of 2nd gear. We thought it was a lose set screw, but once we tightened it up it did it again. Any ideas?

 

[Rivets]

Please post your units model numbers so we can see which transmission you have.

 

[Froglee69]

My husband found a broken pin and he replaced it and it seems to have worked. Thank you so much