What makes a CV Joint make a popping or clicking sound?

Question

I recently bought an "old" 1996 Dodge Dakota. When I turn left in a tight circle, I hear a pop or a click on the front-right side of the vehicle. I was told by the previous owner that it's the CV joint. Sure enough, I was under the car yesterday replacing the idler arm and saw grease sprayed all over the place around the CV joint near the wheel. I didn't inspect it much but apparently the boot is ripped somewhere.

My question is: What makes the joint click? I did a little research online and someone said it's when the grease around the joint goes away and the bearings inside move around. And that when you turn hard, they "drop" and that's the pop you hear. Seems like it's a bit of a stretch that I could hear bearings drop over the noise of the engine. So what causes the clicking noise?

Answer 1

The ball bearings are involved, but the noise isn't because they are dropping. What happens is when the boot splits, the grease starts oozing out (less lubricant) and dirt gets in causing wear. One of the jobs of grease is to take up excess slack in the joint (not that there is much in the first place when it's not worn out). This will quiet any noises out of the joint. If it wasn't there, you'd hear the clicking, but it would be very soft. Now, throw in some dirt/grime and the joint will start wearing faster, creating slop where there wasn't any before. When the wheel is straight, the ball bearings don't move all that much. When the wheel is turned, the ball bearings move quite a bit. When it isn't worn out and the grease is in there, the noise is very much softened and you don't hear it. When it is worn out, the ball bearings will move to a point, then give way. In this process it "pops" to the end of it's travel, causing the popping noise you are talking about.

A CV joint will last quite a long time. Most of them die under the circumstances you are describing with the loss of lubricant and protection of the boot from the elements.

Answer 2

The balls do not "click from side to side". As the balls shrink due to wear they are no longer thick enough to prevent the bearing spacer from hitting the joint housing as it passes by the housing. a joint with proper specs will not click at all, even when dry.

Answer 3

The clicking noise you describe is almost certainly down to the CVJ. As they wear they give out this distinctive clicking on turns and load. As the CV joint is part of the hub, steering, and brakes assembly and can effect the operation of them, the best thing to do is change the delinguent joint.