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: Removal/Installation
To remove the head restraint, pull it up while pressing the stop-catch.
To install the head restraint, insert the legs into the holes while pressing
the stop-catch.
WARNING
Always drive with the head restraints installed when seats are being used
and make sure they are properly installed: Dri ...
Mazda 6 Service Manual: Anchor Bracket
Anchor brackets for securing childrestraint systems are equipped in the vehicle.
Locate each anchor position using the illustration.
To install a child-restraint system, remove the head restraint. Always follow
the instruction manual accompanying the child-restraint system.
Anchor bracket loca ...