Spur gear stripping

[Tmaxxman7]

I was driving my tmaxx down the road when it stopped moving, at first I thought it was a drive line but the spur gear was stripped. So I bought a new one 2 day put it in and it did the same thing. Anybody know why it is doing this? Thanks

 

[EaglesSJ]

The motor could be setting to close or too far away from the spur gear and the teeth are not meshing right.

A write up on this can be found here:
http://www.misbehavin-rc.com/pit-lane/pinion-spur_gap/tm-pinion-spur_gap.asp

 

[SteelCityNitro]

I always check to make sure the engine is properly aligned with the spur gear, meaning that the clutch bell is square with the spur gear. Make the engine mount screws snug, not tight and push the clutch bell on to the spur until it's tight. You can then take a peice of note book paper(you only need a thin strip) and spin the spur gear by hand and feed the paper in. Run it back and forth a few times, and then WITH the paper still between the clutch bell and spur, tighten the mount screws comepletely. Remove the paper and you're good to go.