Look for dirty rollers. Remove the roller and clean it in degreaser or kerosene. Replace the roller and apply some mechanical oil. Oil all rollers twice a year.
Insert a screwdriver into the adjustment slots on the side of the garage door opener unit on the ceiling to move the door lock bar into proper position.
Straighten crooked door tracks, and use a screwdriver to tighten the screws on all brackets.
Check the batteries in the external signal units.
Check to make sure the springs for the garage door are in good condition. There are two types of garage door opener springs: torsion and extension. Extension springs are located above the rails on either side of the garage door. The torsion spring is a single, long spring mechanism across the front of the garage door opening.
Replacing the Opener
Use a socket wrench to remove the bottom and top bolts from the door release handle at the front of the garage door opener. The door release is the "J"-shaped bar connected to the top track of the door opener and the top of the garage door. Stand on a ladder and remove the bolts from the strip above the garage door motor unit with a socket wrench.
Remove the safety lenses and wiring from the bottom corners of the garage door tracks. Stand on the ladder and remove the bolts from the front metal bar holding the garage door motor unit in place. Carefully drop the unit to the floor.
Remove the wires that lead to the wall switch for the garage door opener. Remove the bolts from the center post bracket above the garage door, and carefully drop the entire center piece (garage door motor unit and center rail) to the floor.
Assemble the center guide for the new opener. Place the end in the original garage door opener bracket above the garage door. Place the motor unit on the top of the ladder at the other end of the assembly.
Lift the garage door opener motor unit up and reattach it to the original metal brackets. Reattach the "J"-shaped door opener bar to the center rail and to the top of the garage door. Install the new unit's electric eyes in the same position as the previous monitors, run the wires up to the motor unit, and connect the wall switch to the motor unit.