A mechanic once explained to us that the BMW CV joint never fails: Instead, the BMW CV Boot fails, causing the CV joint to self-destruct. One almost never happens without the other happening first. That's because the BMW CV boot is the guardian and protector of the heavy-duty grease that keeps the CV joint lubricated. If the boot cracks or breaks, the lubricant escapes, and the joint runs dry. It doesn't take very long for the CV joint to wear out completely when its supply of lubricant disappears, and you get the familiar clicking, clunking sounds of a bad axle.

What's our point? If you keep a close eye on those black rubber BMW CV boots, and get them replaced as soon as you spot any signs of cracking or damage, your CV joints will last the life of your car. Or close to it, anyway. The irony is that replacing CV joint boots requires just as much labor as replacing the CV joints themselves, since you have to pull the axle to do the job right. Well, at least you save some money on parts!