GL type freewheels have 160.. Series ball bearings that are used to center the inner race with the outer race. The torque forces are transmitted from the shaft to the inner race by means of the key and from the outer race to the external area by means of screws. Shaft tolerances must be h6 or j6 and outer race key tolerances H7. Either grease or oil lubrication must be applied to the freewheels before operation, following instructions given on page 12. Each freewheel is supplied with two paper gaskets that must be inserted between the outer race and the flanges. If they are not used, the freewheel could be badly damaged.