it's all in the weight of the vehicle. when I ran my rustler and tc3, I never used loctite.. not even on the pinion's grub screw.

on this truck, I need loctite on the pinion and motor screws, or else I can't get one run in..

all back together now, trying to get ahold of a buddy to help video it, w/ GPS on board..
went to 18/46 gearing, so we'll see if it does 40 like your calc says :)