Question about Sears Craftsman LiftMaster Chamberlain Garage Door Opener Wireless Keypad Model 976LM Security+

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I have replaced the gears

I replaced the worm gear and drive gear on my craftsman 1/2 horse opener. When I first tested it, it sent the door down with such force that it continued to run even after the door was completely shut and this resulted with the upper carriage being sent into the cable pulley near the header board. I released the lower carriage via the emergency release only to find that the door was jammed closed. I had to released the curved door arm from the straight door arm to get the door free. I now have everything mechanically in place (after almost being decapitated when the cable/chain tension released) and now I am a little aprehensive to turn it on in fear that I will get the same result. What might be wrong?

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Try backing off the down force and up force pots it sounds like the new gears are working to good, so backing adjusting the pots will make the door stop before it kills anyone. they normally are located side by side and take a screw driver to adjust. They should have an arroww indicating which way makes them use more force.

good luck.

Posted on Dec 10, 2008

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