Bloodzone

I had my gear oil changed 2 years ago while having a new rear spring installed. Rear started clicking at low speed turns. I drained my oil replaced it with dino 80W-90 and added the posi-lube. Working like new again. Can anyone tell be if old gear oil should be this black after 2 years and under 8K miles. This may be completely normal. I've never done this job myself and the old oil looks very black.

73racevette

Hard to tell from the pictures, but the color seems fine. There looks to be something floating on it. If this is water or something besides a bad picture, you may have reason to worry. Otherwise, you are probably fine.

Bloodzone

I think thats just residue from the used cooking tin. Car has not seen rain or a water hose in 2 or 3 years.

New oil sure did the trick. Nice and quiet.

GTR1999

Gear oil is nasty smelly stuff, I still don't like the smell of it after all the years of working on these diff's. A good quality 90 wt or 85-145 Dino oil is all you need. I change mine out about 8k miles as well but many go much longer.
I use 2 bottles of GM additive since they changed the part number a few years ago.

Dusky

When I opened my diff there was very little oil in it, and ofcourse I spilled it all over me. Those clothes are for the bin!
Oil doesn't look too bad. Depends a bit on the oil and what was left in there too.