If they have a lot of give you may want to consider replacing them.
How to level a garage door with springs.
This will tighten the screws and raise the door.
A problem with the spring tension could cause the door to open or close unevenly improperly or at the wrong speed and adjusting the springs will likely solve the problem.
To rise the side of the door that is lower turn the set screws in the drum clockwise.
Open it just as wide as you can without hitting the garage door opener s stop bolt and place a clamp on the track on both sides to keep the door in place.
First the floor may be so out of level that the garage floor does not meet the bottom edge of the door.
Once the spring is free of tension remove from its track hanger.
If the garage door is level tighten the set screws 3 4 turn past the point at which they meet the hollow shaft.
Start with the side which is opposite to where the gap is.
Garage door springs offset the weight of the door and allow it to open and close with ease.
If the door was closing too quickly move the spring to the next higher hole on the bracket.
Climb up to the drum and use a marker to make one mark on the drum and another approximately one fourth of an inch above the mark on the drum if the gap under the door is 1 inch or more.
If the gap is less than an inch make the marks one eighth of an inch apart.
Remember to release the vise grip each time you get to step nine.
Move to the other side of the garage door where the gap is.
However an out of kilter garage floor may require leveling when two critical scenarios happen.
Adjust the springs on both sides of the door the same way.
If it was opening too quickly move it to the next lower hole.
So with a gap on the left side you will begin leveling on the right side.
Remove any safety cables from the springs before loosening the springs themselves.
Second and far more critical is when the garage floor has begun to tilt backward toward the house.
Garage doors come in different styles that use two different types of springs.