All axles should have a shaft seal. I understand how a full floater works. A semi floater actually transfers some weight on the shaft, where as a full floater the shaft only turns the hub making a full floater a stronger axle. I only suggested taking the wheel off so it would be easier to mess with.

I'm not sure what you are talking about how does the oil gets in the housing. You fill the plug on the diff and it fills the housing up end to end. If you look at the plug you'll notice its about an inch higher than the bottom of the axle tubes so when you fill the up the plug the oil can flow out to the end of the housing and lubricate the shaft bearings. There should be a seal at the outer end of the tube that the shaft goes through to keep the diff oil from leaking out the tube.

I've rebuilt a couple of axles and that's what it appears to be.

 

There is a Shaft Seal, i had to replace mine about a month ago.
What I had to do.

1. Pull the wheel and Brake Caliper off.
2. Open the diff
3. Push the Axle in to the diff and the Retaining clip falls out.
4. The Axle will just pull out then, and you can see the seal on the end of the Axle Housing.

that is what I did to replace mine.

 

there is no retaining clip azlo. That1guy, i hope you didn't think i was being a dick. I just saw the truck in your signature and assumed you were talking about a semi floater. I will look into the seal. There are no seals in the system except the seal on the back of the hub that holds the inboard bearings in, and the axle flange seal. I just meant if there is a seal in the side of the diff, then what would be the purpose of it. Unless the axle housing had its own fill and drain plug, there would be no reason to have a seal where the axle plugs in to the rear end if you fill the housing and it "leaks" or fills the housing? ya know what i mean?

 

Not at all. I was just trying to show we were on the same page. Did you replace the axle flange seal you speak of?

After spending half an hour looking at pictures and part numbers. The only other seal I see listed for the aam 11.5 axle besides the pinion seal is the flange seal which napa i thinks calls a wheel seal. This is probably what you need.
http://www.napaonline.com/Search/Det...+50022+2022079

 

I replaced the big seal on the back of the hub, which stopped the **** from leaking out the back. The flange seal was good, there was no leaks around it at all, so i just RTV'd it and torqued the bolts back on. I still had a real small leak coming out of a couple of my wheel studs (I swear to God) so I ran RTV around all of those too. So far no leaks. Rear end is still full. I don't know what else to do? Looks to be G to G.