ORIGINAL: nitrosportsandrunner
i had the same issues with 2 different tt-01's i had. just couldnt seem to keep the pinion and spur from eating eachother. they didnt like brushless, even with a 2s lipo and drift tires!
now i run a redcat lightenting. say what you will about redcat, but that car is bullet proof. i run a 3s lipo in it, jump skate board ramps, go off roading with it. nothing seems to hurt it! and i have yet to have any issues with the spur/pinion or diffs.
my theory on the tt-01 is that the chassis flexed enough to effect the gear mesh. they run great with brushed motors, but in my experience dont fair as well with a brushless setup.
and i never did like the tamiya's motor mount. just give me a mount with a slot hole so i can adjust the gear mesh myself, instead of doing it by the number of teeth on the pinion. that just limits gear selection.
not trying to knock tamiya. their stuff is the most realistic looking out there. and many of their models are super strong.
The newly designed motor mount and cover on the TT01 type E now allows for a more direct motor fit without the wobble that was seen with the older design (standard TT01) and hence does not effect the mesh as was previous noted.
The above will still happen with a TT01 type E if using the standard 19T/61T pinion and spur as the material is weak, hence the racing gear set and harder pinions are required!