Replacing GDO box (motor) only. Which one?
It appears that my LiftMaster chain-driven 1/2HP GDO circa 1999 is dying. (See my post a few lines below.) Looks like the problem is with the motor. It might be just easier to buy a new box and attach it to the existing assembly. The chain, the drive, the springs appear to be in very good shape -- I don't see a reson to replace them.
Can I just buy any LiftMaster/Sears/Chamberlain chain-driven motor (the whole box you attach up to the garage ceiling) and put it in place of the old one? I am wondering if the chain connection to the motor would be compatible? Are they pretty much standard for this manufacturer?