WD-40 is a degreaser, which could remove remove lubricant and dry out the garage door springs. This can cause unnecessary friction in the springs and lead to early failure. While WD-40 has many valuable applications, it is not recommended to use it on your garage door's springs.
First, know which parts you have to lubricate. These should all be included in your regular maintenance schedule. Springs: The springs that help lower and lift your garage door should be lubricated regularly.