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: Instrument cluster configuration
1. Connect the SST (WDS or equivalent) to the DLC-2.
2. Input vehicle information following the directions on the screen.
3. Select Module programming.
4. Select Programmable module installation.
5. Select the following items and perform procedures according to directions
on the screen.
...
Mazda 6 Service Manual: Oil seal (differential) replacement
1. On level ground, jack up the vehicle and support it evenly on safety
stands.
2. Drain the oil from the transaxle.
3. Remove the front wheels and splash shields.
4. Separate the drive shaft and joint shaft from the transaxle. (See DRIVE
SHAFT REMOVAL/INSTALLATION.) (See JOINT SHAFT REMOVAL/ ...