Inside the axle housing there are little rings that sit in the tubes. One of mine fell out when i was changing my birfields, does anyone know what the purpose of the ring is? Just curious. In the pic of the knuckle the ring is laying down in the axle tube.
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I had the same thing come out of my axle housing when I rebuilt my front end, but there was only one on the driver side and nothing on the passenger side. It was chewed up pretty good and I didn't see anything about it in the FSM or parts diagrams so I left it out when I reassembled it. I'm still building my truck so I haven't actually driven it yet, but the only thing that I could think it could be is some kind of axle shaft guide. But you would think that it would be like a seal or something if it were and it would be pressed into place. You might want to try posting in the pre 84 tech section for more results. I too am curious to find out what it was; more importantly, how to I find a replacement since I tossed mine!