Inner axle seal confusion on knuckle rebuild

[fordoford]

Hey everyone. Rebuilding my front knuckles and seemed to have finally gotten everything apart on the first side. I just pulled the inner axle seal, but now behind it, further into the axle, I see a very similar looking part sitting in the housing. Looks like an axle seal but just seated on the inside, and I can move it around. What is this and what do I do with it?

Another question. This part and it seems the inside of the axle housing has grease somewhat covering everything. I assume this should not be the case and I've only ever heard of oil leaking into the Birf, not grease leaking into the housing (seems crazy to say, but I'm very confused). My Birf also looked fine with no oil leaked in.

I'll attach a couple pictures of the inside seal and what the housing looks like inside, as well as the grease I scooped out with my screwdriver.

Any advice appreciated. Everything was going very smoothly until now

 

[baldilocks]

That part is a stamped steel ring that is apparently pressed into the axle tube at the factory rather than welded. It aides in guiding the axle shaft through the seal and toward the splines of the differential carrier.

I’ve had one come dislodge and so have a few other members here. When it happened to my axle housing it just so happened that I also had the third member out so I was able to thoroughly clean the grease and oil out, reposition the ring vertically in the housing and then tack weld it securely into place.

Reference the other end of your housing to see correct position and orientation.

 

[mudgudgeon]

Looking at the amount of gunk in there, I'd seriously think about pulling the third member out to make it possible to clean the housing out thoroughly.
To already have axles out, you're 90% of the way there.

As @baldilocks suggested, gives you an opportunity to reinstall the metal ring too

Looks like there may have been water contamination at some point.

Also, remove the entire axle breather and check it is not clogged with gunk, including the fitting in the axle housing, hose, and the little valve on the end.