Hi guys. Thanks very much for trying to help me out. The vari-flo I have is an SP-710. I noticed that the 'non-metallic bearing cover' (as it is called on the instruction sheet I have for it is broken and just about completely gone. Might this be causing the problem? I'm nearing wits end but am adamant to fix this as it has become my personal challenge. Is there any other info can I provide that would help the troubleshooting process? Thanks again. Rick