Make sure you put the black cup back on the end of the motor shaft and that it is pressed all the way on. Make sure the RPM sensor is plugged in. If neither of these are the issue, then you probably did not have the motor shaft pushed all the way back when you tightened the coupler after replacing the worm gear. Loosen that coupler up and from the front of the motor (opposite end in which the coupler is on) push the shaft back as far as it will go. Hold it there while you tighten the coupler back up and then try it.

Thanks don. I thought this was the issue as well. I did this the second time when I looked everything over. I think that this is not the issue but I will triple check it again. Thank you for the reply.

I checked the motor shaft tonight. Same type of results. Would go a short distance then reverse. Unlike in the past, it did not blink 5 times. It only blinked once. Any help???

1 FLASH
Safety reversing sensors wire open (broken or disconnected).

Ok. I do not have the owners booklet, so where is the safety reversing sensor wire located???

The safety sensors are the sensors in the garage doorway and the wires run from them to the motor unit. The solid white wire from each sensor runs to terminal #2 and the white wires with black traces go to terminal #3.