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: Moonroof (Some models)
The moonroof can be opened or closed electrically only when the ignition is switched
ON.
WARNING
Do not let passengers stand up or extend part of the body through the open
moonroof while the vehicle is moving: Extending the head, arms, or other parts
of the body through the moonroof is dan ...
Mazda 6 Service Manual: Wheel hub, hub spindle pre-inspection
Wheel Bearing Play Inspection
1. Position a dial indicator against the wheel hub.
2. Push and pull the wheel hub by hand in the axial direction and measure the
wheel bearing play.
Maximum wheel bearing play
0.05 mm {0.002 in}
3. If the bearing play exceeds the specification, replace a ...