Missing Rear Differential Breather Valve - Hole now gunked up

Was working on taking care of the rust on my rear differential only to realize that I had no breather valve. The rear diff itself does not appear to have the symptoms of a clogged breather valve. The area surrounding where the valve should be appears to have been discharging some oil. I changed the oil on this a couple months ago and from what I could see of the inside it looked good and the spent gear oil looked OK, no obvious chunks of metals or anything alarming. I have no idea if it was changed during its 225,000 mile history. The four wheel drive works fine, I've only used it a few times. I don't notice any issues. I will be getting a breather valve but I'm wondering if there is anything I should try to help remove that gunk or if it is a big concern or not that much. Any input welcome!

Here's a video showing what I could see.
https://www.youtube.com/watch?v=w1jeHeNuOxQ

 

The only thing I'd really be worried about that this point, is not so much chunks of metal, etc.. but rather what liquid contaminants could have made their way into the diff. You say a few months. Has it rained in that time? driven through puddles, washed your truck, etc...

I'd be changing out the diff fluid if there was any chance water got in.

 

I bought the truck in December and who knows how long it has been like that. Could've been years unfortunately. I'll definitely plan on changing out the oil again. I guess I'm curious as to the configuration of that hole and how much stuff is in there and then potentially in the main section of the axle/differential.

 

I would get a brass safety valve w/nipple for breather tubing, should be available at any hardware store worth it's salt.

The brass should be soft material to install & change the differential fluid afterwards, right away!

 

Why that over the stock breather valve?

 

I suggested the brass in case the breather valve threads might be compromised. If the the threads are okay, go for the OEM.

 

Yikes! If it were me, I'd do a drain/fill a few times. Looks like there is quite a bit of something there.

 

Configuration of the hole? Are you sure you're looking at the breather?

 

Ya it's definitely the breather, same location as your picture. I'm just wondering if it is merely an open hole, it doesn't look like it from my video

 

I agree that it doesn't look like just an open hole in your video. I tried to google for some images of the empty axle housing, and while I did find some, I didn't find ones with enough detail there.

I could see there being a baffle in there to stop oil from directly "splashing" out of the breather, but someone with an axle housing laying around, or someone willing to go out to their rig and remove their breather will have to chime in to let you know for sure.

It's not terribly difficult to pull the 3rd member, but it's a ton of work...

Edit:
Found a 3rd gen pic with some detail. There does appear to be a baffle there.

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