The conditions which you describe for your differential are signs of a typical high-mileage unit in my experience. They don't last forever and they are a challenge to work on for most people.
If we ban that guy from owning tools, then I will then need to turn mine in.
Sorry about your bad luck on that one.
Take a tape measure to the junk yard or Pick-n-Pull and find a six lug axle close to the same width as what you have. Pull the cover to check the condition.
Carl
Last edited by 52Carl; 04/26/2015 1:50 AM.