Thanks for the advice. So far only a spring steel pin has been used. How much play (to and fro) does the shaft need? Why is it not one solid peice? I think the pin and splines went out because the shaft mount bolts on the S/C housing (the 4 surrounding the shaft) were all loose for a long time. I suspect that it moved too much and caused undue stress on the unit. I need to remove the shaft to assure that the pin is not lodged in the case and then reinstall.
