I recently found a heck of a deal on a 99 sportsman 500 and while going thru and over it i checked the front hub fluid. One side had none and the other size had crud all over the end of the fill/drain plug. I tried draining both to see what was in them and nothing came out of one and the other looked VERY thin and VERY dark brown. Is there a way to clean the insides of these hubs without taking them completely apart? The awd works just fine after I added fluid, but I know what's soaking/running in that fluid and don't want any trouble from it

 

instead of the drain take the cap off like this.

How to Drain and Replace Hub Oil on a Polaris Sportsman 4x4 ATV - YouTube

 

With the caps off you'll be able to clean out any crud that's in there.

 

You can drain it that way,but to really clean the hub inner housing, bearings along with the roll cage that may have some deposits without taking it apart, you can fill back with kerosene or naphtha at 12 o'clock position until it spills out of the fill hole. Install the plug and spin the wheel back and forth several times then pull the cap off. That clean kerosene/naptha will be brown when it drains.Wont hurt the hub seal,plus if you have an air nozzle,LIGHTLY shoot air through the fill hole to blow out any excess fluid through the front bearing. This will dry quickly,then you can do the same on the hub fluid. Fill at 12 0'clock until its FULL. Put the plug back in and rotate several times to get the hub fluid all the way back,then drain at 4 o'clock position. Wastes a little fluid this way,but better than taking the hub apart to get any residue. Did that on a lot of machines that came in with burnt fluid or dry.

 

Thanks guys, I think i'll try both methods just to make doubly sure that it's all out and clean! I just want to make sure that I don't have any more problems with the awd since i've already had to do the bypass on it. Would it be better to take it all apart to clean it or will this accomplish the same thing without disassembly?

 

If you notice any accumulation of oil residue behind the rotor or inner strut,then yes better to tear it down and replace the hub/strut seals. Then you'd have a good reason to clean everything up by hand.If no leaking noticed at the seals,machine apparently just run low on fluid from neglect,then I'd just clean it up with solvent and refill the hubs and give it a try.

 

From what the guy told me he only rode it a couple times a year with a sprayer over the last 7 or 8 years and he sold it because the awd quit working. And from what I can tell he only changed the engine oil as well, but I'll take a look around the back side of the rotor and that whole area and go from there. Are these the ones that I can use (i think 75w-80) gear oil in? This is my first 4x4 with the outboard hubs.

 

Demand Drive fluid only in the out board awd system!Only takes a little per side and a bottle will last a while. The front diff you can use 80/90 as it's the same as "Polaris Angle Drive fluid" they recommend.

 

Ahh ok I knew I could use it somewhere I'll pickup a bottle of the demand drive fluid this week. I put some in it over the weekend but It was only 2 or 3oz in each but I would think that should be enough to show any signs of leaking out of the back or around the end cap shouldn't it?

 

Apparently there is no kerosene around to be bought on a Saturday around here and I have no clue where to even look for naphtha. Can I use gasoline or some other spray type cleaner like carb or brake cleaner?