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: Starting the Engine
WARNING
Radio waves from the key may affect medical devices such as pacemakers:
Before using the key near people who use medical devices, ask the medical device
manufacturer or your physician if radio waves from the key will affect the device.
NOTE
The key must be carried because the key c ...
Mazda 6 Service Manual: Service warnings
HANDLING REFRIGERANT
Avoid breathing air conditioning refrigerant or lubricant vapor.
Exposure may irritate eyes, nose and throat. Also, due to environmental
concerns, we urge use of recovery/recycling/recharging equipment when
draining R-134a from the air conditioning system. If accide ...