AGMA 8a compound gear oil for worm drives. At Craig Generating Station we used a Conoco product called Inca Oil in the worm gear drives for our coal conveyor tripper cars .Seems I recall that Inca Oil started out as a steam cylinder lubricant. It has been 18 years since I retired and I can still remember that because I wrote the original PMs for the unit 1 and 2 coal handling system thirty five years ago. I do vaguely recall that we replaced the Inca Oil in those gear drives with a synthetic oil. Probably a Mobil product.