Steady State, Low To Moderate Speed, No Front Wheel Slip, Forward Direction
WARNING: This page is about a different car, the 2004 Chrysler Pacifica. However, it is still accessible from the selected car via links, so may be relevant.
During normal driving conditions, (no wheel slip), the inner shaft (front axle) and outer race (viscous coupler) are running at different speeds due to the different gear ratios between the front and rear differentials. In this condition, the outer race is always spinning faster (overdriving between 5-32 rpm) than the inner shaft. When the BOC (Figure ) is running under these conditions, at low vehicle speeds the drag shoes and the cage keep the rollers up on the left side (forward side) of the inner shaft flats. This is what is known as "overrunning mode." Notice that when the clutch is in overrunning mode, the rollers are spinning clockwise and with the outer race, thus no torque is being transferred.
NOTE:
Low speed, forward and reverse operation is identical, just in opposite directions. (Figure
) shows forward direction in reverse the rollers are on the other side of the flats due to a reversal of the cage force.