The 00 grease is the way to go if you can keep it in. The problem with normal grease on gears is that it gets flung off and won't return till it gets hot enough to melt it. The Indians when they started building Enfields in the sixties started using 00 grease in the gearboxes because they couldn't keep the oil in them. Fitting sealed bearing in those gearboxes solved the problem and you can keep oil in them.
