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: Installation of radio system
If a radio system is installed improperly or if a high-powered type is used,
the CIS and other systems may be affected. When the vehicle is to be equipped
with a radio, observe the following precautions:
Install the antenna at the farthest point from control modules.
Install the antenna fe ...
Mazda 6 Service Manual: Head Restraints
Your vehicle is equipped with head restraints on all outboard seats and the rear
center seat. The head restraints are intended to help protect you and the passengers
from neck injury.
WARNING
Always drive with the head restraints installed when seats are being used
and make sure they are pro ...