1. Verify that the joint shaft is not twisted or cracked.
2. Turn the joint shaft by hand and verify that the bearing rotates smoothly and freely.

Drive shaft
Joint shaft removal/installationMazda 6 Service Manual: Smart Brake Support (SBS) (Some models)
The Smart Brake Support (SBS) system alerts the driver of a possible collision
using a display and warning sound if the radar sensor (front) and the Forward Sensing
Camera (FSC) determine that there is the possibility of a collision with a vehicle
ahead while the vehicle is being driven at abo ...
Mazda 6 Service Manual: Radio Reception
AM characteristics
AM signals bend around such things as buildings or mountains and bounce off the
ionosphere.
Therefore, they can reach longer distances than FM signals.
Because of this, two stations may sometimes be picked up on the same frequency
at the same time.
FM characteristics
An ...