Full rubber O.D. radial shaft seals are subject to spring back after installation. Although this may be caused by poor installation methods, the root cause of spring back is shear forces acting against the installation direction. The affect that this has is primarily related to the position of the primary sealing lip. Both the contact width and the outer face position can vary axially as much as 0.060” (1.5 mm). Cocking can also result from uneven spring back. Both of these scenarios can reduce the life of the radial shaft seal. If the bore has a draft angle, then the spring back distance will be exaggerated and more likely to be a problem.
Parameters Affecting Sealing: