How do I fix a sectional garage door problem?

Question

Halfway on the down travel the door starts to "rock" like a seesaw. When this rocking starts the door almost wants to "jam". What should I be looking for or replacing? I've lubed all the joints,sliding points,new rollers,new springs,cables,greased the slider track and chain for the opener.

Answer 1

It is possible that you have more spring tension on one side than the other.  Try to equalize the tension and make it strong enough that the door almost goes up by itself.  This is done different ways on different doors.

Answer 2

if this door has extension type springs the sheaves ( pullies ) there should be 4 per door, check these for bearing wear!

Answer 3

If you've done all the lubrication that you said, the only other thing would be to check the actual door tracks on each side of the door to insure that they are properly aligned and secure.

Answer 4

The answer above is correct. The load in the sheaves increases as the door lowers. They can look normal to the inexperienced eye. They can even look normal when off the door. Change all four, especially if the door used to work well. Make sure the front pulleys do not rub against the track assembly. Space them out with a washer.