Chassis flex was an issue in the nitro 8ight chewing up its fair share of clutch bells and bearings. The fix for the nitro version was to give this car slightly more gap in your gear mesh.

This may work for the electric version as well - if it flexes enough under hard driving/rough landings that it put sstrain on the pinion and rotor shaft and bearing.

You should space your steering servo up off the chassis too