open and close

[BCCLEW]

sears opener 13953640srt gears wore out i took it down put in new gears.put it back marked all wires before i took it down.i touched no adjustments that i could see. green lights are on steady on door sensors. with the door hooked up or not door goes down about three seconds then reverses. on the up limit switch contact it hits in the up position but never goes long enough to hit the down contact.so my ? is why is this happening?WORKED fine before ps i am and auto mech,so fixing things is usually not so hard but having said that i am not a garage mech. thanks for any help.

[Lone Star Charles]

It sounds like the RPM sensor is not picking up the rotation of the motor shaft. There is an RPM sensor (part #17) located just outside the bracket that holds the worm gear and there is an interrupter cup (part #18) that fits over the end of the shaft. It's real easy for the cup to slide a little ways off the shaft and as a result, the RPM sensor will not pick up the rotation of the motor. The controls think that the door just hit something and so it will reverse. Usually you can push the cup onto the shaft just a little bit further and this will fix your problem.

Let us know if this helps.

[BCCLEW]

Re garage door

Right on pal pushed sensor in about and 1/8 inch works great made adjustments and its fine, another man mabe prob. Thank again bcclew