There was an awful popping noise when turning the car left or right. My father and I did a basic checkup of all the the suspension and steering components, but didn't find any glaring issue. I drove the car to a local mechanic and his suggested repairs were to replace the strut mounts and that the CV joints had a bit too much play in them. The car has 192,000 miles on and the quote was more expensive and we wanted to spend, but we were confident in being to complete the repairs for a fraction of the cost ourselves. However, when removing the driver's side CV joint a gear fell out of the differential. Picture attached is where the gear fell from...


Is this common? Am I screwed? Sorry for my ignorance this car was inherited from my wife and is the first Mazda I have ever worked on. Any insight is appreciated...

 

What engine size what transmission? Can we have a picture of the gear that fell out?