I have a 07 rancher fm. I dont have a real problem with getting water in either of my diffs but I was wondering if anybody has tried to use those boots that are used on some wheelers like the Suzuki vinson? It seems that no water could get into them unless it had a hole in it. I dont know what it is called but I will try to find out.

 

It is called a case breather. They are about $10. It may be worth a try.

 

Is your vent hose still on tight?they can work lose, and mounted high in the frame or to the air box?