I have a 2002 Sportsman 500, I have 2 questions.

Do you have to use the Polaris brand of hub fluid or is there another fluid that is ok?

Do you have to use the Polaris brand of front gear case fluid or is there another fluid that is ok?
My bike seems to get a little water in the front gear case every couple hundred of miles, the seals don't appear to be leaking.
My best friends bike is the same way.

 

use the polaris hub fluid for the front hubs... tranny fluid can be used but i have heard problems with the front hubs engaging without warning

 

If your not going to use polaris hub fluid then use Mobil 1 synthetic ATF. that's what I use and haven't had any problems. Alot of people use plain old gear lube for the front diff but the polaris stuff is only like 2 or 3 bucks for a 8 oz bottle. you can use mobil 1 gear lube but it's 15 bucks a bottle and you only use 4 oz in the front case. The one thing you need to stick with polaris is the tranny/chaincase lube. it's a but pricey at 10 bucks a quart.