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: Liftgate disassembly/assembly
1. Disconnect the negative battery cable.
2. Remove the liftgate lower trim.
3. To remove the liftgate outer handle and liftgate key cylinder, remove the
rear finisher.
4. To remove the stud ball, separate the stud ball and the stay damper.
5. Disassemble in the order indicated in the table.
...
Mazda 6 Service Manual: Foreword
When the customer reports a vehicle malfunction, check the malfunction
indicator lamp (MIL) indication and diagnostic trouble code (DTC), then
diagnose the malfunction according to following flowchart.
- If a DTC exists, diagnose the applicable DTC inspection. (See DTC
TABLE.)
- ...