Confused!!!
 

I have 2 different bits, both new.
One is Honda S2000, that I got it today and the other is Nissan Gloria and I got it yesterday.
Just a while a go I noticed that the sound from S2000 is a little bit more noisy than the Gloria's. At first I thought that was the motor from S2000 because its 3.0 intead of Gloria's 2.2. I change motors, gears, axles between them and still the sound was less smooth on S2000. And when Im trying to rotate the axle with my hand, I need, lets say, a gram more force.
I don't understand what is wrong.
Could that be the chassis?
:confused: