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: Automatic transaxle fluid (atf) inspection
Automatic Transaxle Fluid (ATF) Condition Inspection
One way of determining whether the transaxle should be disassembled is by
noting:
If the ATF is muddy or varnished.
If the ATF smells strange or unusual.
ATF Condition
Automatic Transaxle Fluid (ATF) Level Inspection
Caution
Th ...
Mazda 6 Service Manual: Picture Quality Adjustment
WARNING
Always adjust the picture quality of the rear view monitor while the vehicle
is stopped: Do not adjust the picture quality of the rear view monitor while
driving the vehicle. Adjusting the picture quality of the rear view monitor such
as brightness, contrast, color, and tint while dri ...