Well, IMHO, it is fairly common. Went through 2 CV joints on my Porsche over a 6 yr period. Both were bearings breaking up. And, I lost one CV joint on my Dodge Ram. That was the bearing holder/race that cracked. In fact, it looked similar to the imaged posted.

CV joints do fail. Of my three, I do know that two had cracked boots. The Dodge (one cracked boot) had seen extensive off road and numerous mud excursions. The Porsche was strictly street but both CV joints showed signs of rust but only one boot had visible cracks.

John Stewart
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