Yup, when the boot tears, all the grease slings out, dirt gets in there and there goes your joint.

BMW didn't use the highest quality boots, the ripping boots are a common problem. The CV boots on my '84 chevy blazer (beater ride) are original with 150k miles on them. And its a GM product!?!?!

See the articles on the home page about CV boot replacement.

good luck!