Harold is right on the money. Go to John Deere shop and get corn head grease. As a farmer I can add that the hotter it gets the better it works, Of course one does not need to worry about heat and a steering box unless it is close to a header. When poly lube type grease came out in the mid to late 70's the best way to check; place a marble size squirt on a steel surface and hit hard with a hammer. If it splatters its not poly. I still use poly in all my steering boxes but, Harold has changed my mind. Ed
