Front Diff Leaking

I just noticed that my front Diff is Leaking oil. There was a 3" puddle after a week of sitting in the same spot. I noticed that the half shafts have 1/4" or so of movement where they go into the diff. It’s leaking from the drivers side axle shaft.
One of my questions is dose everyone run their RZR’s in 4×4 all the time or just when absolutely necessary? It handles so much better on this track I go too that I like to keep it in 4×4. But I could see it being hard on the front end parts.