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: Transaxle range (tr) switch inspection
Operating Inspection
1. Verify that the starter operates only when the ignition switch is at the
START position with the selector lever in P or N position.
If not as specified, adjust the TR switch.
2. Verify that the back-up lights illuminate when shifted to R position with
the ignition ...
Mazda 6 Service Manual: Fuel tank inspection
Caution
Disconnecting/connecting the quick release connector without
cleaning it may possibly cause damage to the fuel pipe and quick release
connector. Always clean the quick release connector joint area before
disconnecting/connecting using a cloth or soft brush, and make sure that it ...