My OFNA Nexx8 makes a lot of noise when i runt it
The noise comes from the gears
I am running a 13t pinion on the motor and the main diff gear is a metal 46t

please help me to reduce the noise as it is much more than what i have heard from other cars

check the motor pinion and spur gear mesh.. it should be such that a paper can go inbetween those and come out zigzag but not torn . search the net its better explained there.

Check for dirt/stones stuck in the gear
I face this problem on my XXT's plastic gear. I dont know if the problem exists with a metal gear set.

it's clean... so that clears that dirt is not a reason

Ok. Try what Pravesh said. You may notice increase in noise if the mesh is tight..

^^That. The spacing should be about as this as a sheet of paper. The better way to set mesh is to have a feel for it. You can start feeling when the mesh is too tight and can hear it. It will come with experience. The paper method should work fine.

If the Pinion and Spur is metal you will hear noise when the car is on the move.. This why the factory gives Plastic Spur to reduce the noise. Other than that Mesh the gears with a paper in between them, when you roll the car the paper should come out without tearing. Call me if you need help.. Murali Here..