Originally Posted by Maj_Overdrive

The TT01 motor mount has 6 or 8 holes in it and each set of holes corresponds to a specific pinion. You simply pick the set of holes that correspond to your pinion and that's it, no other adjustment needed. You also have to use Tamiya pinions on those cars because the gear pitch is a weird in between pitch. There is a pitch (32p?) that seems to matche the Tamiya, but you'll never get the mesh right on the motor mount since the Tamiya is cut differently. Just trust me that you can only use Tamiya pinions on the TT01.

Edit: I'm pretty sure the manual is available online at Tamiya but if it's not I can post a pic from it if needed.