With metal gears, its not just greasing, there are huge noise and efficiency benefits from running the gearboxes in. I use fine valve cutting compound to bed them in, then dismantle and clean it all off with a toothbrush and WD40 (or any degreaser).

I then either:

Put a smear of plain old high melting point car/motorcycle greases in each brass bush, and all around the gears. Then cover the box and run it to fling the grease off before reassembly.

or

Spray the boxes with motorcycle dry chain lube. This stuff soaks right down into every surface and then the solvent evaporates off, leaving dry grease behind that will not fling off.

The gearboxes on my Bulldog went from 'high pitched shriek' to 'silky smooth hum' after doing this, so I do it to all gearboxes nowadays.

Rob G