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: Cooling system service warnings
COOLING SYSTEM SERVICE WARNINGS
Warning
Never remove the radiator cap or loosen the radiator drain plug
while the engine is running, or when the engine and radiator are hot.
Scalding coolant and steam may shoot out and cause serious injury. It may
also damage the engine and cooling sys ...
Mazda 6 Service Manual: Using Automatic Locking Mode (Some models)
Follow these instructions when using a child-restraint system, unless you are
attaching a LATCH-equipped childrestraint system to the rear LATCH lower anchors.
Refer to “Using LATCH Lower Anchor”.
NOTE
Follow the child-restraint system manufacturer's instructions carefully. If
you are no ...