Craftsman 1/2 HP Garage Door Opener

Unhook the safety release and operate the door by hand. It sounds like the door is binding.

For starters, pull the "emergency release" rope to disconnect the arm/traveler from the screw/chain. See if the door can be run up and down by hand. If not, the problem is in the door. If you can, then the problem is in the door opener.

I've been operating the garage door manually - I can open and close it easily. Any suggestions what could be wrong with the door opener?

imho:

Could be what you mentioned, limits. The new sproket could be causing a toque trip. Get your door openner adjusted, and check for level and plumb.

tom @

Recheck your sprocket installation. Something may have happened there.

try lubing the door whens the last time you oiled ind greased it properly?

if your like me it was when the door was installed over 20 years ago.

my door appeared to move easily but had intermittent jams, from worn rollers and bearings i found lubing it.........

No, because the only opener that is having a problem is the live one. If your door mis-aligns itself with the electric opener then the door IS the problem. Anyone can manually open a door and correct the alignment to make it work, but an electric garage door opener can't make these adjustments. It's not smart enough. The other opener should be smart enough to know it's has to be the door.