Diagnosis
The door itself is binding, causing the opener to jerk. The likely cause is worn or dry rollers, or a bent section on the horizontal track.
How to Fix It
Disconnect the opener and run the door manually. Feel for sticking points. Inspect all nylon rollers for cracks, chips, or flat spots. Replace any damaged rollers. Lubricate all rollers, hinges, and the track's contact points with a silicone-based garage door lubricant. Do not use WD-40.
If That Didn't Work
Check the horizontal track alignment where it meets the vertical track at the header bracket. The tracks must be perfectly level and aligned. A slight bend here causes the rollers to bind and chatter. Loosen the bracket bolts, tap the track into alignment, and retighten.
Heads Up
If the door has steel rollers, they are likely the source of the noise. Replace them with nylon rollers. They are quieter and won't rust.