[fox46]

Don't worry about the grease "flying off". All you need is a light film to protect the gears. If you put too much in it will begin to churn around the gears like a pump. Although it may look like there is no grease on the gears there is in fact a light coating. Too much will zap huge amounts of power and generate a great deal of heat, eventually causing the grease to melt and leak out onto something that doesn't like it nearly as much as the gearbox... likely a C-Rio or some electronic doo-dad according to murphy's law.

The grease inside the fisherprice gearboxes is garbage- I would bet it's made from congeiled McDonalds fryer waste. The FP boxes are not made to last and as such they put the cheapest lube in them they can find. It will not tolerate high heat, is not meant for metal gears and is prone to drying up into the consistency of something resembling ear wax. Your best bet for greasing gearboxes like those would be a good synthetic spray lube like HHS2000 made by Wurth. It sprays on from an aerosol, dries to an excellent consistency for small gears, withstands high heat very well and is easy as pie to spray through a little hole if you wish to reapply. It's actually quite a phenomenal product- it has a unique "stickyness" almost like an adhesive where it sticks to anything and everything making it great for high speed applications but terrible to get off your hands - especially because it's water repellant.