Sears 1/2 hp GDO reverses direction

pensacolianDecember 21, 2008


Lots of good info on thie forum. thank you.

I have an older unit without the door sensors. I recently replaced the drive gear. After restarting it reversed direction twice due to force on down movement (I forgot to adjust the limit switches before I turned I back on.) Now it will only run down for about 2 seconds then it reverses direction and stops. It does this with the door connected, door not connected and even with the chain off the sproket. I tried adjusting the force screws but that made no difference. I tried running it with the speed sensor plug disconnected. Same result.

During intallation of the drive gear, the instructions said to disconnect the speed sensor. At that time I wasn't quite sure where to disconnect it so I didn't. That didn't seem to be a problem, but I thought I'd mention it in case there's something involved there I can't think of.

I appreciate any advice you may have. Any ideas?

Pensacolian (1st forum entry)

Thank you for reporting this comment. Undo

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 none 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.

    Bookmark   December 22, 2008 at 10:07AM
Thank you for reporting this comment. Undo

Thanks Don. the black cup cap was in place, but one of the leads from one of the RPM sensor lites, the red one, had come loose from the circuit board. I simply soldered it back in place and was back in business. It was this forum that taught me enough about the syustem to know what to look for. All is well now.

    Bookmark   December 23, 2008 at 10:22PM
Sign Up to comment
More Discussions
Need a professional locksmith service!
Hey guys, I am new to this forum and the reason I registered...
Metal fence panels - steel or aluminum? Best brands?
I want to put up a fence to divide my side yard from...
Jacking house up
Ok the first time I posted in wrong place. I'm going...
Water Drip Stain on Roof Fascia?
My roof edge on the corners of the front porch is leaving...
Curtain Rods
Hi, I am not sure where to post this so my apologies...
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™