Light-duty lubricants, such as WD-40, are only suitable for cleaning the tracks of an automatic garage door. Because an overhead garage door opener has a heavy workload, a sturdier lubricant than WD-40, such as silicon spray or motor oil, is required to keep it operating smoothly and quietly.
WD-40 is the trade name of a household spray lubricant manufactured by the WD-40 Company. The WD stands for water displacement. The spray's original purpose was to displace water from metal parts before assembly to prevent rust. The primary ingredients are mineral spirits which dissolve grease and dirt, mineral oil for lubrication and carbon dioxide as a propellant. This combination makes WD-40 popular for many tasks around a home or shop such as stopping squeaks, cleaning metal and combating corrosion.
Your overhead garage door opener is expected to work reliably and silently throughout the year. No one wants to spend much time maintaining a garage door, so a lubricant must remain in service for months. A garage door weighs hundreds of pounds, so a thick lubricant is needed to endure the high mechanical stresses. Finally, since most garages are not heated or air conditioned, the metal tracks and drive assembly of an opener require a lubricant that can withstand wide temperature variations. The mineral spirits in WD-40 evaporate within a week of the initial application, leaving only a thin layer of mineral oil. Mineral oil alone cannot lubricate the high-stress parts of a door effectively nor can it survive the heat of summer or the chill of winter. Therefore, WD-40 is a poor choice to lubricate a garage door opener.
Instead, use a lubricating silicone spray, a commercial garage door grease or regular engine oil to maintain your garage door. While silicone spray is more expensive than WD-40, it can be applied just as easily. If you live in a cold climate, make sure a commercial grease is recommended for low temperatures. No matter which lubricant you choose, be sure to protect all the moving parts of your garage door opener. Start by greasing the hinges and make sure the rollers are spinning freely. Oil the springs to protect them from rust. You do not need to lubricate the length of the track, but lubricant within the track's 90-degree bend will quiet squeaking and oiling the lowest two feet of the track inhibits corrosion and will prolong the life of your garage door. Lubricate every six months.