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: Antilock Brake System (ABS)
The ABS control unit continuously monitors the speed of each wheel. If one wheel
is about to lock up, the ABS responds by automatically releasing and reapplying
that wheel's brake.
The driver will feel a slight vibration in the brake pedal and may hear a chattering
noise from the brake system ...
Mazda 6 Service Manual: Automatic Transaxle Controls
Various Lockouts:
Indicates that you must depress the brake
pedal and hold in the lock-release button to shift (The ignition must be switched
ON).
Indicates the shift lever can be shifted
freely into any position.
Indicates that you must hold in the lock-release
button to shift.
N ...