Trying to Diagnose Bad Differential

Just a followup, I ended up replacing two axles ($300 each) and replacing two spider gears (also in the ballpark of $300 each) I put the diffs back together with the help and expertise of a local mechanic for $150. And then reinstalled the differentials and axles myself. Including the sealant and more gear oil (about six and a half gallons), the whole job cost me about $1600 in total. Not too bad considering I only have basic tools and a cherry picker, and I did it out of my driveway. I just wanted to drop an update in case another amateur mechanic wants to know what it costs in the future.

 

Its all just nuts 'n' bolts. Good job!