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: Heater core inspection
1. Remove the A/C unit. (See A/C UNIT REMOVAL/INSTALLATION.)
2. Remove the heater core from the A/C unit.
3. Inspect for cracks, damage, and coolant leakage.
If any problems are found, replace the heater core.
4. Inspect for bent fins.
If any are bent, use a flathead screwdriver to stra ...
Mazda 6 Service Manual: Front shock absorber inspection
1. Remove the front shock absorber from the vehicle.
2. Inspect for damage and oil leakage.
3. Inspect the rubber bushing for deterioration and wear.
4. Compress and extend the shock piston at least three times. Verify that the
operational force does not change and that there is no unusual nois ...