i am building my tt01d kit i just got and i was reading in some posts and it said something about locking the differentials. what does that do?? and do i lock the front and rear differentials?? how do i do it??

start off with ur diffs open. as you learn to drive i would suggest locking the rear as it makes the back end swing out easier. the simplest way to lock it is to remove one of the three bevel gears in the diff case and fit it between the other two so that the gears do not rotate.