Thanks for the reply. It took me a while because I could not locate 7545 service manual you suggested. I ended up paying for a WC7556, since I understand majority of the parts are the same between the two models.
However, this 1436 page document is overly complex, and I do not know how to find the possibly stripped gear (or other suggestions) for my particular problem. The scanner continues to grind... and search words like "scanner" "grind" doesn't yield any beneficial results, nor is there a section that addresses bad scans or grinding noises.
How do I use this manual OR -- where can I get the part number for the gear that you speak of so I can try replacing it?
Thank you very much in advance.