On a 1999 Polaris Sportsman 500, what is the correct fluid for the front transmission?

 

If you're talking about the front gearcase/differential, your 99 uses regular gear oil. Polaris calls it Angle Drive but any good 75w-90 or 80w-90 will work.

 

 

No, those are bleeder screws to bleed air out of the brake system.

 

 

I made the same mistake on the first car I owned. Brake bleeder screws look a lot like grease zerk fittings, but the end is shaped different. They both come in all kinds of sizes, shapes and colors, but bleeder screws are usually tapered so a hose can slide over the end, and grease zerks are usually more rounded.