IMO if you are stripping spurs you have a problem somewhere else and using a steel spur for that is just a temporary band-aid. You might be getting some flexing of the chassis at the motor area when you go WOT. When the chassis flexs the spur/pinion can come out of alignment. Traxxas does sell a chassis brace for this


http://www3.towerhobbies.com/cgi-bin...?&I=LXMHV3&P=Z