I tried a "real John Deere place" or as close to one as i could find in California, and they had never heard of Cornhead grease either. This was a place that sold full size tractors and such for the hay and alfalfa fields, rice fields, etc. in the ag areas that still exist in some parts of northern California. I get the feeling from what I've read and experienced that this may be something particular to the combines and reapers sold in the midwest for harvesting grains like wheat and corn. I ended up mixing lube in to thicken up some 90W oil for my steering box a couple of weeks ago. I figured it was better than using straight lube or gear oil (the other options that I was left with here). So far so good. I may bite the bullet and fork over some serious bucks for the PenRite (sp?) stuff at some point.