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: Front and rear fog light switch inspection
Light switch LH side
1. Remove the light switch. (See LIGHT SWITCH REMOVAL/INSTALLATION.)
2. Inspect for continuity between the light switch terminals using an
ohmmeter.
If not as specified, replace the light switch.
Light switch RH side
1. Remove the light switch. (See LIGHT SWITCH ...
Mazda 6 Service Manual: Front upper arm inspection
1. Remove the upper arm from the vehicle.
2. Inspect for damage, cracks, and bending.
3. Inspect the ball joint rotation torque.
(1) Rotate the ball joint five times.
(2) Measure the rotation torque using a suitable allen socket and a
torque wrench.
If not within the specification ...