1988 Yamaha Big Bear 350 4x4 (all time) leaks oil somewhere near the tranny

I put the bike in 4 HI, and no issues

I put the bike in 4 LO, and it leaks pretty bad.
I am assuming there is a bad seal there, however I am confused as to why is leaks in 4 LO only. Can anybody provide any insight?

For now I will run it in 4 HI, as the bike is not work taking the tranny apart to fix a seal.

Any other ideas of how I can keep it from leaking?

Thanks!