I've used them with good success. I would not use them for something still available through deere. Take your serial number to the dealership and order a manual it should be around $40. The link below shows all the manuals avail for that combine by serial number. If you order through your dealer you will have a better shot at getting a manual matched to your machine.
-paulhttp://www.deere.com/servlet/com.deere.u90785.productcatalog.view.servlets.PublicationsSearchServlet?userAction=publicationsSearchResults&entryPoint=other&tM=FR&searchCriteria=6600&language=english&submit=Search This post was edited by FarmerZeb at 22:14:43 06/21/13.