The cover bearing is toasted. I pulled it out today. Luckilly, I bought a bearing and oil seal a while ago and have them on hand. 

I finally got to take the cover off and look at the clutch. There is a hellacious amount of dust that I assume is from the belt slipping. The light grinding noise is from the cover bearing retainer it appears that the retainer is bent out on the end opposite the screw with grind marks. I need to check the bearing it looks like it could be damaged. I did'nt notice any shaft play, the one way works and it turns quietly.
I still have to remove the secondary. Do you by chance know if the secondary nut is left or right threaded?

Thanks for the insight! I'm hoping to solve this issue without going into the wet clutch. I saw a video online that attributed the wear to the harmonic balance being off and vibrating on the shaft. I found the inner sheave for $99 and the outer for $119. I may just replace both and start new. A new cam is about $30. Hopefully, that and a fresh belt solves the issue.

Hey all... I have a question on  21 zforce 800ex. I recently rode a few days at HMT without issue. After getting back  I noticed a slight noise in the clutch area that sounds like lightly grinding brakes when idling. I noticed the bushing on the sliding sheave is toasted. I do not see this in any parts diagrams online. Is this bushing available or does the whole sheave need to be replaced? I also bought the cover bearing. Has anyone changed the bearing and seal in the cover without the specialty tools?

Hey all.. I have a newbie question for a 2018 cforce 500S. I have looked all over and cannot find torque specs for the valve cover bolts. I see the specs for the head. But nothing for the valve cover. I did the valve inspection /adjustment and every one was tight. They are all mid spec now and I want to close it up.