Oil or grease ? If your shiftbox is tight and has no leaks mineral gearoil SAE 90 is great to use , but elsewhere soft grease is recommendable.
John Deere Cornhead Grease.... the stuff is amazing, be sure to watch the video linked below.... http://www.greenpartstore.com/John-Deere-Special-Purpose-Corn-Head-Gun-Grease-AN102562.html Video: http://www.youtube.com/watch?v=UEwk_sYP6A8
Gear case and grease Combiner As far as i know the grease is a multi purpose grease. Nothing spesial with it. I have been using it for many years and yes on a Deutz fahr combiner.
It's Special ! Because , being John Deere , it's of course GREEN........ . I see they have Moly grease a few rows down , I'd use that .