gear oil in air filter housing

[DerekCanuck]

Been having issues with my CTIS of late and once I rebuilt the CTIS fittings with new orings I was able to narrow the last leaks down to my two front CTIS seals.  Strangely enough it seams the leak at the CTIS seal has also tried to blow the oil up through the vent to the air filter.
 
Anybody ever have this happen?   I have heard of the transfer case vampire story but haven't found any write ups indicating the hubs losing their oil to the air filter..
 
 

[Monk]

The only reason I've ever had pressure was a spindle seal OR a groove in the little spindle nipple.

Did you replace the spindle seal recently? First time I changed my seal, lol I had a bigger leak and re-replace much gentler


I can only see that seal #20 be the issue as that would pressurize the vent lines,...

Also check around to make sure no vent line it melted closed or something plugged it..

[GreenMeanie]

This is exactly what happens when those seals stop working,
air will pressurize the hub sending oil to the least path of resistance,
which means you got oil being pushed up through the vent lines.