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: High Beam Control System (HBC) (Some models)
The High Beam Control System (HBC) determines the conditions in front of the
vehicle using the Forward Sensing Camera (FSC) while driving in darkness to automatically
switch the headlights between high and low beams.
Refer to Warning/Indicator Lights.
While driving the vehicle at a speed of ab ...
Mazda 6 Service Manual: Fuel pump unit inspection
Caution
It is normal to hear the fuel pump operating when the ignition
switch is turned to the ON position.
Note
To improve startability, the fuel pump control operates the fuel
pump unit when the ignition switch is turned to the ON position. Due to
this, fuel pressure is rapidly ...