...air box... or so I thought.
It turns out the oil was coming out of the rear gear case vent tube and being sucked into the air intake, instead of blowing out, as well as leaking onto the exhaust causing a burnt oil smell, yuck. Of course when I first saw the oil I thought the worst, that my rings or valve seals were toast... I was ever relieved to discover the actual cause.

My question now is, how do I stop this? When I changed the rear gear case oil I filled it as specified in the owner's manual so why would it be leaking? The oil in the case looks like new, there is no water that would increase the volume.

I've seen some other ATV brands with a plastic accordion type thingy on the end of the vents that expands as pressure increases but does not allow oil out (or water in) as it is not an open vent. I'm not sure what the correct name is for these or where I could get one that's the correct size for the vent hose. Any ideas?

I bought the machine used last summer, it has a little over 5200 km on it and runs like a top with the exception of the rear axle, the splines are worn so there is some slop in the mag side rear wheel. I plan to do a complete rebuild of the rear axle later this summer but is still rideable for now.

 

Hmmm.. not sure how to fix.. but replying so I can keep tabs of the answers

 

Had the same problem, huh?

We are not alone...
https://forums.powersportsnetwork.co...047-427-1.aspx
http://forums.atvsource.com/viewtopi...=46864&start=0
(read further down this one)

 

I do have some oil in my Airbox -- I was always "TOLD" that it happens due to off-camber riding... I would love to NEVER have oil in the airbox again if there is a way to fix it! So bascially ya - same problem!
-Steve

 

As a quick fix, we need to find somewhere else for the final drive vent line to go, somewhere away from the air intake... maybe a longer piece of hose so we can bring it up to where the oem location is but then route it back down to the bottom of the chassis so any spillage doesn't end up in the air intake, my foam filter is ruined.

 

I can't promise that this is a fix but it has worked for me. When you put the oil in the diff until it overflows it is over full until the excess drains out. I think most people just fill it until it flows out and put the plug in. I wait until NO more oil drips out of the fill hole. Then I replace the plug. So far I have not had any problems. It may be this has nothing to do with it and I have been lucky regarding whatever the real cause is. I would love to have this confirmed or disproved. Since it is happening to yours, if this stopped it we would have an answer.

 

I went for a ride last night and when I got back I checked the oil and it was about an inch low. I'm starting to think that my bearings may be going out causing some heat buildup.

 

i would make a small baffle box hose in bottom from diff then one out top to original location or just a small air filter on top. then it vents and exses drains right back to diff

 

I'm going to try a Ski-doo injection oil filter on the end of the vent hose, hopefully this will hold what it spits out and it will drain back into the case when I'm done riding.

 

So East-West,

How did the Ski-Doo oil filter work?

-CS-