Motorcycle Repair: 1999 Vulcan Nomad noise, check engine oil, mechanical seal

Question
Hi Mark,I have a 1999 Vulcan Nomad 37000mi There is a noise sounds like metal to metal coming from the right side down low gets real loud at times and just goes away this has happened around a dozen times. I've pulled the cover off the right crankcase.Bearings everything seemed to be fine.I took a ride the other day and it started again and found a little antifreeze under the water pump.someone told me when it started making noise to use a stick by placing it to my ear and trace it.I did and went all over the engine and it was extremely loudest around the water pump.So I took the water pump cover off removed the impeller.The impeller was corroded and looked like black gunk on it also gunk on the water pump shaft.The mechanical seal looks ok.There is a O ring on the shaft that I can turn with my fingers.Could this be my problem? If so what parts should I replace. Your help will be greatly appreciated.
Thank You...Don

Answer
Hi Don,

I suspect the engine's water pump shaft, water pump sprocket, and/or mechanical seal are defective.

I would need to view the parts to accurately diagnose the actual cause and to determine which parts are defective.

Check engine oil for evidence of coolant. Let me know what you find.

Respectfully,
Mark Shively