Problem with Stanley Garage Door Opener

[rparks3]

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.

[Tony Hwang]

Hi, Does the open limit switch works OK? Maybe door travels too far up almost jamming. I have a Genie screw drive opener. Both open and close limit switch needs proper positioning. Good luck,

[rparks3]

I think my problem is the carriage assembly or the part that rides the bottom of the screw with the rope to disconnect the carriage assembly. The screw gear is worn. If I replace this my problem should be resolved. WolfpackRon.