I have a NEW craftsman 139.664956 T rail (no eye sensors) made in 1983. I bought it when I had a problem with a Genie 401 screw drive BUT I fixed with a used brass carriage carrier,
Well the carrier wore out and after 47 years of service I decided to replace it with my 30 year old chain drive opener.
I set the new one up on the floor to be sure it operated and set approximately the limit switches and then proceeded to lift the new one into position.
I did NOT use the remote or the receiver. I temporarily am running it on a 25 foot extension cord as my Genie was hard wired. I also ran the unit on the floor with the same extension cord.
I did not lube anything yet.
I did not have the door attached to the carrier.
I pressed the switch (door bell style) and the carrier goes about 10 inches and reverse. I did this a few times and then I released the carrier from the trolley mechanism with the same results of ten inch travel and then reverse to start position.
I then loosened the cable / chain tension and verified that the chain is around the sprocket and the cable around the white plastic pulley in the nose.
This did work on the ground.
I repeat this is NEW and THIRTY YEARS OLD.
Thanks