Stepper motor

I was wondering has anybody had a motor that has had some slop in the motor itself or is it related to pinions and such.I move my z-axis up and down and the shaft of the motor moves as I move it. prt alpha motor
Thanks, Bruce

Have you checked the pinion gear to verify that the set screws are still tight?

A stepper motor, under power, will not have slop. The gearbox on some motors may have a minimal amount of play, but the TH gearbox on the Alpha 7.2:1 motors are virtually back-lash free.