My CX5 left front hub is making a thumoung sound. The car only has 28,200 miles on it.
Has anyone has a hub/bearing problem with their CX5?

 

Did you mean thumping sound?

As for a hub needing to be replaced it is also the the years in service as well the miles that can effect their service life. So no it is not uncommon but not necessarily frequent.

 

Welcome to the forum

 

It's like a thumping sound that mirrors speed. I checked the tire and it does not show cupping or abnormal wear.

 

well 2 choices go to Mazda service or go to a local Firestone in your area that can raise the Mazda up and completely inspect your running gear, chassis and suspension. Unless you can do the same and have the equipment and knowledge to find the problem then it is better to have it done professionally.
firestone in knoksville tenn - Search



Basically however what you are describing is actually is tire damage? GUESSING!!! I unless you are experienced selling and serving tires and have experienced many aspects of tire defects and damage you may have missed what may be a damage tire on your Mazda?