Garage door very jerky when attached to opener

[hoopsam]

Garage door opens/closes smoothly manually, but is really jerky in both directions when hooked up to the garage door opener. Any ideas?

I have checked all of the nuts/bolts to make sure they are tight, lubricated everything & replaced a couple of hinges, but it is hard to isolate the problem because when I detach it from the opener & manually open & close it, it seems to run in the track smoothly enough.

I have a chain drive opener from sears, about 6 year old.

[gdoorpro]

Extension springs?

Sounds like you may have extension springs on your door and the 4 pulleys (two on each side) may have worn out bearings. Replace the pulleys and you will probably be good to go. If you have torsion springs above the door, it may be something else, but their are bearings that can wear out their, too.
Lets start with the door components. Run the operator detached from the door. Does it operate smoothly? If so, it is prabably the door. If not it could be gears going bad.
Ryan