RE: WHAT DO I DO ABOUT GEARING.
what motors you running, stock titan or a 540? it its a titan and your running off road than you need to go with at least a 18t pinion and 6cell batteries. traxxas only mentions using 7cell batts with the 23t(high speed pinion) and on road. and many here will tell you that traxxas overgears for good speed ratings. this will burn up the motors fast.
if you have a 540 motor, than you need to use a pinion with 2-3t lower than the number of turns of the motor.
example. if you have a 15turn motor, than use a 12-13tooth pinion.
im not talking out my butt, iv done everything wrong with gearing already. i ran a titan off road with 23t pinion and 7cell, and i then got a 15t motor and used the stock gearing(18t) and burnt up that motor.