If you seal the winch with RTV so no water can get in you need a vent so the thing can breathe. @Blackjack sells one. It has a fitting that goes on the bottom of the winch motor case, a tube that routes to the engine bay and has a small lawnmower breather or you can drill a hole in your air box and put a barb in it.
If it helps, here is my installation for the thing - scroll down about halfway...
https://www.doubleveil.net/jeep/fifty-three.htm
