[happy024]

Yesterday I changed the my differential gear lube front and rear in my 95 YJ. The front D30 oil looked ok mainly a grey color. But the rear D35 was BLACK and there was a black film built up on the inside of the cover. Not very thick maybe paper thin. I also noticed the spider gears that sit verticaly some of the gears are looking a little baby swiss cheese like. Little indents on about a quarter of the gears. And the gears that go horizonaly the edges are feathering a little. The rod that conects the 2 horivonal gears is a little sloppy in there.
I am planning on regearing after I get moved to Ohio. So I guess my questions are-

What is the black from?
What can I do in the future to keep this from happening again?
Can I tighten the rod inside the spider gears?
And any other coments or help would be great.