Breaking half-shafts?

My friend Alex was having trouble getting enough drive with his Slash 4x4 at our local indoor high-bite track.  We switched the center diff to a slipper clutch to get more power down for the whoops section, but he had the slipper tightened all the way down.

As a result, there was nothing in the drivetrain to absorb the shock of wheel/motor RPM mismatches, and the weak link in the drivetrain broke – yup, you guessed it, the thin little plastic prongs on the half-shafts.  After 3 sets of these things, we figured it out.

So if you’re breaking half-shafts on your Slash 4x4, check that your slipper is not set too tight!  You need it to be able to slip in heavy shock loads to the drivetrain.