As in all CFM products everyone needs to check all...and we mean all..bolts and mounts for correct torque or missing parts..first. Then if you have an issue like your shifter problem, we find many have not been adjusted correctly so...that will be your next step. If it has been popping out of a range for a while, and the detent alignment is correct, that is unfortunately an indicator of a bent fork or damaged gear/dog in the transmission.