a) Manually Engaged AWD
In the manually engaged AWD, a connection between the differentials of front and rear axles is realized over a manually operated clutch. If the clutch is opened, the vehicle is then driven by the front or rear axle as the case may be.
A simple design with positive-engagement between the drive shafts leading to the front and rear axles does not allow for speed differences between the axles and is mostly operated manually.