More likely is that the inner piece that moves the selector plate or the selector plate itself has worn out its lobes. Both are plastic and wear out much faster than the outer selector.
Grand Poobah of T.W.A.T.
RETIRED (for now)
GUN DOCTOR-Fix, Upgrade, Custom Builds.
I build nearly indestructible Lipo-Reliable Mechboxes.
Owner, The Digital Smoker E-Cig Shop