I am having a problem with a Stanley garage door opener model SD450. It
is a screw type unit. The door opens and closes with very little
resistence manually by hand. The door opens perfectly with the garage
door opener. When I try to close the door with the garage door opener,
it make a noise at the start of closing, but will not close without
assistance. It makes this noise at the beginning and several times
during closing. I can get it shut using the garage door opener by
helping it along as it closes. Any suggestions as to what my problem
might be? Thanks in advance. WolfpackRon.