The female part (slotted) of the ball & pin type universal is machined directly on the .6250 dia fan shaft. The .6250 shaft is ground down to .5906 to give a shoulder for the inner race of the bearing. In the area where the pin engages the slot, the female universal is 63 Rc. The split clamp rings at both ends prevent any for or aft movement of the fan shaft when turning the fan. The fan shaft bearings are ceramic hybrids; ABEC-7 grade.
