I recently discovered that white lithium grease is a much more
appropriate lubricant to use than WD-40 when it comes to items that are
open to the elements.
It provides a thick coat that stays in place and won't freeze.
The technical name for it is Cerflon, which uses a carbon-flourine
bond to form a ceramic reinforced fluoropolymer.
WD40 wasn't designed as a lubricant but as a Water Displacer.
If you want a lithuim grease, better get a lithium grease paste (commonly sold as "white grease"). This liquid wrench stuff contains 40-70% tetrachloroethylene, one of the rather nasty family of chlorinated hydrocarbons. Take care not to get that on your skin.
A fellow I went to school with (and who had a part-time job as a car mechanic) once washed his hands in tetrachloroethylene. The skin on his hands then started bleeding from the pores.