I'm betting on the rear axle. I suspect missing teeth on a ring gear (or spider gears if its an open differential) and the broken chunks floating around in the housing caused the near lock up.

The sad part is that if you broke the rear axle under power, you probably hurt the overrunning clutch as well, and it will fail the next time your pushing the car a bit hard.

Sounds like you have a good wife, do whatever you need to do so she stays around, good and understanding ones are rare to come by. Gene