Initially development of the SKF Grease Test Rig V2F was carried out to check greases for railway companies. This was to ensure that there was no leakage from the axle box when train wagons were subjected to regular shocks upon passing rail track joints.
Leakage could occur because the grease in the vicinity of the bearing could fall into the bearing due to the regular vibrations. It would then work its way through the bearings and, in the case of non-mechanically stable greases, the thickener structure would break and consequently the grease would become liquid and run out from the housing.