[Willie Krash]

I'm still a fan of Lubriplate 288.
Helical gears it seems to me would do better with an oil made for such. Straight cut gears are really levers. The two mating surfaces would be very high pressure on the mating surfaces as opposed to helical.
Helical seem to me to be more sliding in nature, i.e a much larger footprint between the driving and driven gear, more contact surface.
I am not an engineer so I don't know for sure if I have anything right.
I will say SPO288 is slippery and "stringy."