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: Climate control unit disassembly/assembly
1. Disassemble in the order indicated in the table.
2. Assemble in the reverse order of disassembly.
Wire Disassembly Note
Disassemble the wires in the shown in the figure.
Wire Assembly Note
Assemble the wires to the position as shown in the figure.
...
Mazda 6 Service Manual: Variable intake-air system (vis) shutter valve actuator inspection (l3)
1. Remove the air hose. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION.)
2. Disconnect the vacuum hose from the VIS shutter valve actuator.
3. Connect a vacuum pump to the VIS shutter valve actuator.
4. Apply vacuum and verify that the rod moves.
If the rod dose not move, replace the intake ma ...