Differential vent

TXredfish · 04-18-2011, 08:47 PM

I was under my MH checking some things and saw oil on my rear axle assembly.
The oil was on the the axle on the passenger side and between the springs and differential housing. It appears right below the differential vent.
There is no evidence of oil on the brakes or wheel or losing so much oil that is on anything but the rear axle.
I pulled out the differential plug and the oil appeared to be level with plug hole and OK. I checked the differential vent and it was less than hand tight. Could this be the source of the vent leaking and how tight should this vent housing be screwed into the axle? I tightened it down as much as it will go. Is this OK? I cleaned off much of the oil to see if it continues to leak. If it continues to leak, could the vent be stuck and need cleaning or replaced? If I can clean it, how is this done? If it a matter of just unscrewing the vent, removing - cleaning or replacing? What else could cause this leak other than a possible overfill when I had my last oil change?
Thanks for any help ....................

Yaj · 04-18-2011, 08:59 PM

If it was filled then it was very cold, and it wasn't tight enough, heat expansion could have caused the overflow past the threads. Usually when they get pluged up they'll leak from a gasket seal. They are easily removed and cleaned. Clean it and reinstall with some teflon tape and snug it up good, then keep an eye on it!

DriVer · 04-19-2011, 11:11 AM

Quote:

Originally Posted by TXredfish

I checked the differential vent and it was less than hand tight. Could this be the source of the vent leaking and how tight should this vent housing be screwed into the axle? I tightened it down as much as it will go. Is this OK?

Yes that's fine. No worries.

Quote:

I cleaned off much of the oil to see if it continues to leak. If it continues to leak, could the vent be stuck and need cleaning or replaced?

The vent itself does not leak so much as allows pressure and at times some oil to vent through. I have not seen a vent get stuck.

Quote:

If I can clean it, how is this done? If it a matter of just unscrewing the vent, removing - cleaning or replacing? What else could cause this leak other than a possible overfill when I had my last oil change?

Leave the vent alone. Get some WD40 and spray the area and wipe up any excess with a rag. Leave it alone and observe. You should be fine since you have verified that the fluid level is where it should be. Checking, make sure the vehicle is straight and level.

CJBROWN · 04-25-2011, 05:42 PM

Mine does the same thing. Never a drip, just collects some dirt and shows you there's some oil vapor coming out of it.

DriVer · 04-26-2011, 07:05 AM

Quote:

Originally Posted by CJBROWN

Mine does the same thing. Never a drip, just collects some dirt and shows you there's some oil vapor coming out of it.

I concur. Same here!

tims52ford · 04-26-2011, 07:18 AM

The vent is much higher then the fill plug. i can't see how it would be discharging some of the lube. Get youself some brakekleen an clean the area that has been soiled and keep an eye on it. There could be a crack in the housing, I have seen this before on some housings, be a heavy duty truck mechanic. we had two trucks built in the same year with this problem.

DriVer · 04-26-2011, 07:30 AM

Quote:

Originally Posted by tims52ford

The vent is much higher then the fill plug. i can't see how it would be discharging some of the lube.

I have seen where the wetness around the vent cap is condensed vapor once it bleeds past the vent cap.

DancinCampers · 04-26-2011, 10:06 AM

From Nov 2004 thru Nov 2005, I had the coach in five times because differential lube covered my toad and rear of the coach. First, the vent was cleaned. Next the vent was relocated to the frame via rubber hose. Finally, it was replaced with a new style vent, W8002811 I believe, and have not had any problems since.

It was my experience that the vent only leaked when under load climbing long grades ( the hump to Pahrump). The level was checked each time and the WCC center said it was ok.

Just my experience.

DriVer · 04-26-2011, 12:22 PM

Quote:

Originally Posted by DancinCampers

It was my experience that the vent only leaked when under load climbing long grades ( the hump to Pahrump). The level was checked each time and the WCC center said it was ok..

DancinCampers, AKA "Over the Hump to Pahrump!" Stayed at Terribles won $3K.