quick question re innards of D30

I picked up a disco D30 from an 87 4 cyl XJ with 4.10 gears that I want.

I am going to use this housing with the gears all set up (they are MINT!), but install my axles from my 90 XJ non-disco D30 (it is ABS so they have the bigger ujoints and I had just replaced them)

Anyway, I took the carrier out to replace the axle seals and there is an oring on each side of the housing. When I had my 3.55 housing open before I'm pretty sure there weren't any orings in there. I can't figure out what these orings would do? They are about the same diameter as the carrier bearing outside race.

The thing is I can't find these o rings in any schematic of a D30. Has anyone come across these and know part #'s by any chance?

the ones I took out were in pretty bad shape and there is no chance of getting a part # off of them, and measuring would be very iffy at best as they are all distorted and brittle.

I have had a couple of these apart before and asked the same type of quesition...
But..
I looked closer and it looked to me more like left over RTV than an actual O-ring.
my d30 has a small hole on either side of the case inline with the axle tube that was filled with RTV when i first opened it. and I was able to poke in through and clean out all the RTV and it was connected to that O-ring thing.

I went to the junk yard and pulled a couple more out, and found the same type of thing.

I don't know if it is replaceable but i think it was there to stop the oil from escapeing out the axle tube or somthing like that.

It's RTV from the factory, they put it around the tubes when they press them in, just peel yours out and you'll have no problems.

You know, that is very possible that it is rtv - that would explain the very deformed shape of it. It is definitely in a big O but the cross section is not really circular and I had to use a pick around the whole circumference to get it out. I think you are right. Now the next question is what the heck is it in there for? It is between the bearing and the axle seal. It appears to seal the outer race to the housing - maybe they want to keep gear oil from getting in there to minimize the chance of a spun bearing?

Thanks for the input by the way - made me look at it a different way

Thanks 87xjco, I wrote my last reply before seeing yours - that makes perfect sense. i won't worry about it.