some people replace those first stage plastic gears with steel ones from second stage of another drill?

i think that almost all motors with around 3.175mm (1/ shaft fit in most cheap drill pinions, i have replaced some drill motors with better quality johnsons and they work great, i do not recommend trying change steel pinion gears as they crack easily-- wasted gear

my teammate also made cool drill mods by making a new alu case to replace that plastic gearbox, new alu box has double ball bearings (wheel doesnt need ens support!) and useful mounting holes, only downside is that gearbox without motor weights around 700g (unmodified drill is 400g?)

some pics of that mod:
http://www.loisteputki.liitin.net/JH-Q/DSCN3099.JPGhttp://www.loisteputki.liitin.net/JH-Q/DSCN3099.JPG
http://www.loisteputki.liitin.net/JH-Q/DSCN3100.JPGhttp://www.loisteputki.liitin.net/JH-Q/DSCN3100.JPG
http://www.loisteputki.liitin.net/JH-Q/DSCN3101.JPGhttp://www.loisteputki.liitin.net/JH-Q/DSCN3101.JPG