If the door works fine you likely have a problem with the garage door opener mechanism.
Should a garage door opener rail be level.
Most garage door openers include rail segments that fit to doors with heights of seven feet.
The top of the door should be level with the top of the motor unit.
The top of the door should be level with the top of the motor unit.
Do not position the opener more than 4 10 cm above this point.
The first is that it puts the opener lights below the top of the door for maximum light coverage.
The trolley is attached to the motor that opens and closes the garage door.
The parts of a garage door that comprise its driving functions are attached at a 90 degree angle between the door and the garage ceiling.
This is a safety feature installers are taught when installing doors for use without openers.
The instructions then state to open the door.
Do not position the opener more than 4 10 cm above this point.
Adjusting garage door tracks with one track on either side of the garage door they must be in alignment for your garage door to operate properly guiding your door as it is raised and lowered with an extension or torsion spring.
Otherwise it would cause a shadow under the door.
A 2x4 laid flat is convenient for setting an ideal door to rail distance.
The liftmaster model 3280.
Rail segments generally last for a number of years as long as corrosion or mishandling doesn t occur.
A chain much like a bicycle chain is attached to a trolley that runs along a rail.
The opener should head should angle down for 2 reasons.
When installing an opener not many things are put in plumb or level and this is on purpose.
Some modern chain drive garage door openers such as liftmaster s premium series 8360 model have dc motors that make their noise levels much quieter.
The instructions show the header bracket located above the door opening mounted with a 2 inch clearance from the highest point of a sectional door.
The back hang side rails should be lower 2 3 than the elevation at front header to keep the door from closing when not hooked to an opener springs torsion bar alone.
This page has a link to the complete door opener manual.