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: Nonreturn valve inspection
1. Remove the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION.)
2. Siphon the fuel from the fuel tank.
Note
Nonreturn valve is integrated in the fuel tank.
The nonreturn valve is normally closed by the spring force.
3. Verify that the nonreturn valve is closed.
If the nonretu ...
Mazda 6 Service Manual: Valve clearance adjustment
1. Disconnect the negative battery cable.
2. Remove the tire (RH).
3. Remove the splash shield (RH).
4. Remove the spark plugs. (See SPARK PLUG REMOVAL/INSTALLATION.)
5. Remove the high-tension lead.
6. Remove the oil control valve (OCV) connector.
7. Remove the ventilation hose.
8. Remove th ...