Catastrophic failure of Rear diff and repair DIY

[wsmeyer]

I was leaving the house the other day turning right onto the street. About halfway through the turn I hear this loud BANG, it sounded like a backfire. As I was driving straight it wasn't outrageous but I could tell something was definitely wrong. I decided to turn around and get it back into the garage to investigate. As soon as I started turning the sound just got worse and worse. I limped a u-turn and backing into the garage was probably the worst noise I've ever heard from a car.

I could tell it was coming from the rear but from what I can see through the inspection hole the gears look OK so I'm not sure what's going on.