I have a Tac50-04 unit with a Dover D.C gearless G-3-A machine.

I’m getting a 1613, encoder cross check is close to tripping. Then immediately I get a 1609 encoder velocities disagree by more than the “m61” parameter witch is set default to 50. Saftey string opens and car shuts down. I have replaced the encoder, problem still exists. Any direction as to where I should troubleshoot next? Thx you

Did you replace the motor encoder or governor encoder? You might check your governor rope and sheaves. Sometimes rope grunge will build up and change your counts.