In standard design, the MESLU clutch coupling is a pneumatically operated, dry-running double cone friction clutch with an internal bearing. This is characterised by the fact that the inside and outside parts of the coupling are supported each other so that there is a favourable wear pattern of the friction pads caused by the uniform distribution of forces. By arranging the friction drums as a double cone there is also automatic readjustment that takes place with gradual abrasion and wear of the friction pads. The pads are made of high-performance frictional material based on synthetic resin (without asbestos), very safely dimensioned and extremely wear-resistant so that even in cases of frequent gear shifting operations long service life is guaranteed. The outer friction drums provide a highly reliable shifting operation as a result of their good heat emission capacity. Moreover, the clutch coupling does not cause any axial forces, neither in engaged or disengaged condition.
However, based on the special shaft arrangement (Quill shaft) of the 3-speed pump gearboxes of the Inai Kenanga, it was necessary to modify the standard MESLU design. In this case the hollow shaft of the respective gear had to be connected with the outer part and the solid shaft lying inside with the inner part of the clutch. As a result of the solid and hollow shafts of the gearbox supported on one another, the inner bearing of the standard MESLU design could be omitted. However, the weight of the MESLU clutch in conjunction with the large distance of the centre of gravity to the bearing of the solid shaft on the gearbox side made it necessary to have an additional bearing support in the clutch coupling.
The VULKAN experts developed special pneumatic control units as well as a special monitoring system for the shifting logic of the gearbox with the gear blocking required.