Why Ferrari paint the inside of the gearbox

hello all
i have read somewhere that the inside gearbox is paint to prevent from the corrosive action of the oil on the silumin.
Is it true?
And if yes, what can we use to clean inside a gearbox?

I have been told its to speed up the return of the oil to the bottom of the gearbox - a painted surface is smoother. Same reason as the inside of some high performance engines are painted - no idea if its the real reason though!

Andy

The paint used by the oldtimers on the inside of engine blocks was called Glyptol.

It most likely is not conventional paint. As you know Aluminum is pouris so the paint is most likely epoxy to fill in the pours. This prevents the oils from leaking out. My 2c

Steve is right. The paint was to help seal the box. Many transaxle rebuilds and I have found the paint falling off. I have had them paint stripped and I have used plastic bead blasting. I have had the box repainted and I have built them clean. I would use the bead PLASTIC and only "plastic bead" blasting. I would also not worry about the repaint as I have had no leakage with no paint. As for oil drain back, engine yes I have done that, but the gearbox parts are flooded anyway, no real drain back.