What grease does everyone use in their gearboxes? Is it even necessary?
I don’t even use grease.
It’s not super necessary, but I wanted to be firing on all cylinders at Worlds, so I put some grease in my motors and on some gears and sprockets. We use this stuff, which was kindly given to us at Worlds by our friends at 2114X. 
It is definitely slick. I haven’t done a battery of tests, but it seemed to make the rotations on our motors smoother.
White lithium grease liek @Aponthis liked to. Metal 12 tooth gear is the prime spot as it has the most friction being metal. Plastic on plastic gears it is needed less.
Get some q-tips and please wear gloves if possible as it is a pain to get off. Not too gloppy, not too little. You need a thin film to do it right.
https://www.lowes.com/pd/DuPont-4-oz-Non-Stick-Lubricant/3550502
I personally like this. I used it in NBN on my flywheel and i think it worked nicely.
This doesn’t make any sense to me. Can you provide more details on how the 12-tooth pinion gear has more friction than other gears?
white lithium grease; you can find it at any home depot or lowes
White lithium grease works, and we’ve always uses 3-in-1 Oil which worked very well.
@Rick TYler
Steel on steel reference for coefficient of friction:
http://www.engineeringtoolbox.com/friction-coefficients-d_778.html
Acetal references:
https://www.curbellplastics.com/Research-Solutions/Materials/Acetal
http://what-when-how.com/materialsparts-and-finishes/acetal-plastics/
Steel has a higher coefficient of friction than Acetal as Acetal is made to be low friction. Acetal on steel seems good, but steel on steel is much higher. So when you chain 12 tooth gears meshing together, the lithium grease tends to help a lot. The second Acetal link says .35 coefficient of friction which .