CV axle or wheel bearing?

[Shawn]

My Mazdaspeed 3 has been making a lot of rattling over bumps in the front passenger side wheel well. I took off the wheel and started pulling on stuff until I heard the noise. I noticed that there is some play in the cv axle. It will move slightly toward or away from the wheel hub. I think it is where the noise is coming from. What would cause this?

 

[Puffnstuff]

CV joints usually make a popping sound when they are going bad as the joint wears out or becomes unlubricated. A worn out joint could exhibit excess play. How many miles are on the car and do you drive hard? Does the steering wheel provide any feedback while you are driving and this is happening? Are there any tears in the cv boot or grease leaking out of it? Missing crimp seal on the ends of the boot? I don't know what that arrangement looks like on your car but sometimes when ball joints wear out they allow excess play and rattle. I have a ford escape and the front end is notorious for rattling when a vertical link becomes worn. Have you checked the sway bar end links to see if they're still snug?

Truth be told you'd get a better response in a Mazda forum from guys who own this model.