1. Inspect the dust boot on the drive shaft for cracks, damage, leaking grease, and looseness in the boot band.

2. Inspect the drive shaft for bends, cracks, and wear in the joint or splines.
Joint shaft disassembly/assembly
Drive shaft removal/installationMazda 6 Service Manual: Front upper arm removal/installation
Caution
Performing the following procedures without first removing the ABS
wheel-speed sensor may possibly cause an open circuit in the harness if it
is pulled by mistake. Before performing the following procedures, remove the
ABS wheel-sensor (axle side) and fix it to an appropriate pl ...
Mazda 6 Service Manual: Reporting Safety Defects (U.S.A.)
If you believe that your vehicle has a defect which could cause a crash or could
cause injury or death, you should immediately inform the National Highway Traffic
Safety Administration (NHTSA) in addition to notifying Mazda Motor Corporation (Your
Mazda Importer/Distributor).
If NHTSA receive ...