Mazda 6 MPS 2005, Training Manual Supplement

Page: 100 / 112

Driveline/Axle
4WD Solenoid Control Current Is ON
•
When the 4WD solenoid control current is ON, current flows from the 4WD CM to the
4WD solenoid, and the coupling operates in the following manner.
1. Magnetic flux forms at the electromagnetic coil of the 4WD solenoid.
2. Due to the magnetic flux in the armature, the pilot clutch is pulled towards the magnetic
coil side and engages. This causes friction that generates torque in the pilot clutch.
3. The torque is transmitted to the pilot cam, which is engaged with the pilot clutch.
4. Wheel slip at the front axle creates a rotational difference between the pilot cam and the
main cam. Due to this relative torsion, the cam mechanism operates, transmitting torque
from the pilot cam to the ball and then to the main cam. In this way, the push force
exerted on the main clutch is amplified.
5. As the main clutch engages, the drive torque from the front wheels is transmitted to the
rear wheels.
•
The amount of push force exerted on the main clutch by the main cam (that is, the
strength of the drive torque transmitted to the rear wheels) changes in accordance with
the proportion of the force acting upon the pilot cam, engaged with the pilot clutch.
Therefore, by changing the periodicity of the electric current from the 4WD CM to the
4WD solenoid (ON/OFF rate of the 4WD solenoid = force acting on the pilot cam), the
module controls the transmission of drive torque to the rear wheels.
03-20 Service Training Mazda6 MPS Supplement