Figure 3 Shows the principle of operation of the laminates pack 1. The external laminate plates 2. The silicon oil 3. The internal laminate plates

Figure 3 is a diagram showing the difference between the two sets of laminates and to demonstrate how the drive is transmitted.

Consider both sets of plates are running at the same speed and the silicone oil is at a resting temperature. There will be light slippage between the plate sets.

Now consider that the two sets of plates are starting to run at different speeds i.e. when the front wheels turn faster e.g. wheel spin. The oil between the plates becomes agitated by the different speeds coupled with the additional agitation caused by the oil being 'sliced' by the slots and holes of the plates. The nature of the oil is such that when heated it very quickly thickens. The result of this is the plates find it harder to slice the oil and therefore try to close the different speeds of the plates. This can only be achieved by more power being applied to the rear wheels until they catch up. The more they cannot catch up the thicker the oil gets until they do.

There is an overriding factor with the maximum drive that can be transmitted and this is determined by the model variant of the car. The higher the engine output, the higher the maximum drive. e.g. turbo = 90Nm at the propshaft.

This also explains why it is possible to destroy the viscous coupling characteristics by increasing the engine power without increasing the rating of the coupling.

Figure 4 A reconditioned laminate pack ready for installing