most of the time i found it is the little bearings that the savage has now if you go with the flux balk head and there diff set that will give you a stronger set up mainly becouse of the bearing size and if you change your diff case to a jammin crt 1 you can use a bigger bearing on the other side i have also changed my out drives as well to the one that the crt 1 uses and then you can replace the dog bones to the crt 1 universal and it seem to cut down the vibration and every thing stay together better .......... i have done all this and after 8 races no prob at all