:The rear crankcase is a challenging application for radial lip seals. High repair costs make it desirable to seal this area over the life of the engine. One step towards this goal is the combination of sealing system components into one module. Limitations of the elastomeric sealing lip lead to the incorporation of PTFE elements. The recent development of a thermoplastic flange material meeting the high requirements for thermal, chemical and mechanical stability results in weight and cost reduction with a high degree of sealing reliability.