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: Fuel injector removal/installation
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 ...
Mazda 6 Service Manual: Clutch cover inspection
1. Measure the wear of the diaphragm spring fingers.
If not as specified, replace the clutch cover.
Depth
0.6 mm {0.024 in} max.
2. Measure the flatness of the pressure plate with a straight edge and a
feeler gauge.
If not as specified, replace the clutch cover.
Maximum ...