I seem to be missing part T26496 in my engine rebuilding as I can not find any part that look like the illustration. Furthermore, I cannot see how the anything is retained since the screw heads meet the aperture of the cam hub as seen in the photo of the gear. The gear is recessed from the gear face by 50/1000 inch, but bolting a washer would not retain the gear. I have been unsuccessful in finding this part with any vendor Can anyone shed light on this part as to how it works and a source for a replacement?