Dreaded clunk when turning

Ok on a whim, jacked it up spun the wheels and I feel it get stuck, wheels are spinning opposite each other, so not sure grip. Pop off the cover and yep, missing tooth up there on the small gear (is that small pinion?) anyhow the big gear coming from transmission appears fine, then the medium gear for left wheel and the one for right wheel look fine, but the smaller gears are shot. One looks to be missing 2 teeth which is where the clunk came from. Some shavings and parts of tooth in the oil. So now what? Is this junkyard time? Or can I replace that gear with the differential in/on the car.?? I have the manual but I am not real sure what the parts are all called. and bunch of detail about washers and certain spacing etc???? Any help or guidance is greatly appreciated. Hope to do this with my son, . People fix this sorta thing right? Or do they just go buy a replacement pumpkin?View attachment 1715475985
No doubt you have a problem
When you have that much damage and all that metal bouncing around inside the differential you will need to tear down the complete assembly and do a thorough inspection before you determine which parts a ok to use.
Get your credit card out, this is going to be expensive.