1978 CX500, 1980 CX500 Custom
I thought I was at the end of the engine rebuild. I installed the rear case with new seals and mechanical seal. When I put the water pump impeller on the shaft there was not enough thread to install the cap nut. I have the thrust washer between the impeller and mechanical seal and a new sealing washer. If I remove the thrust washer there is sufficient thread to be able to torque to the correct amount. There is about .005" clearance between the rear of the impeller and the face of the rear case. Without the thrust washer I can feel the spring loading of the mechanical seal when I push on the impeller. With the thrust washer installed there is very little front to back movement of the impeller. Is there a down side to not using the thrust washer? Any other thoughts?