Purpose, Function
The crankshaft converts the reciprocating movement of the piston to a rotational movement via the connecting rod.
The main bearing forms an oil film on the outer surface of the crankshaft journal to prevent wear due to sliding.
Construction
Crankshaft
The crankshaft is installed to the inside (crankcase) of the cylinder block.

The crankshaft has a key groove to match timing to the crankshaft pulley.
The crankshaft has the following parts shown in the figure.

The optimized shaft diameter ratio of the crankshaft journal and crank pin has reduced sliding resistance while maintaining rigidity.
The steel crankshaft has five bearings and eight counterweights for improved accuracy in the rotational balance.
The crankshaft journal and crank pin have been induction hardened* to bear high loads.
The crankshaft has an oil passage for supplying engine oil to the crankshaft journal and crank pin.

Main bearing
The main bearing is installed to the outer surface of the crankshaft journal.
The upper main bearing and lower main bearing are made of aluminum alloy.
The upper main bearing has an oil groove and oil hole.
Thrust force is suppressed by the thrust bearings on both sides of the No.3 journal.

Crankshaft Position (CKP) Sensor
Motor MountsDriving In Flooded Area
WARNING
Dry off brakes that have become wet by driving slowly, releasing the accelerator
pedal and lightly applying the brakes several times until the brake performance
returns to normal:
Driving with wet brakes is dangerous. Increased stopping distance or the vehicle
pulling to one side whe ...
Forced Ignition On
NOTE:
In order to perform a forced ignition ON, the M-MDS is necessary. If the
servicing is being done outside of an Authorized Mazda dealership, contact an
Authorized Mazda dealership for instructions.
The forced ignition ON procedure forces a power supply to each part when
...
Precaution
Intermittent Concern Troubleshooting
Vibration method
If a malfunction occurs or becomes worse while driving on a rough road or
when the engine is vibrating, perform the following steps.
NOTE:
There are several reasons why vehicle or engine vibration could cause an
electr ...