I replaced the gears in the 1/2 hp chain driven sears garage door opener and re-installed the motor and all of the other components. I reconnected all of the wiring.

Now I am having trouble setting the timing of the door. I pressed the button on my remote control and it started to run in one direction for only a short distance then reversed in the opposite direction for about the same distance. I can't adjust the timing. I have tried and tried. The light is not flashing so I know it is not a blockage at the beam level.

Please I need some help.