We had the same thing in La. The wind was bad and the really fine dust got, on the jacks and every thing. It sounded like grating steel.
Manual, and on internet says not to use wd40 bu to use only silicone. Spray good, wipe dry especially around the seals.
Our jacks have zerks, for greasing. Where we keep it they greased them.
I am concerned about the conflict, of grease fittings and on the other hand instructions to only use silicone spray. Any grease, it would seem would trap dust and grit and ruin the chrome plating, of the rams and the seals.
Since then they are cleaned and lubed with silicone spray.
Flood the top and seal area and let it run down. wipe off final time to get grit only at the bottom.
Don't want to sound like a know it very little. Perhaps someone has word on using zerks or silicone.
Can't imagine a tech telling someone that contradicts their manul and what they put on the net.
WD40 is not a lubricant. It will strip off any lubricant on rams or whatever. It is a solvent /cleaner.
When I was much younger, people were preaching how great it was for everything. I ruined the bluing on a favorite .22 by using the stuff. It sat in the cabinet after being wiped down with wd 40 and developed fine rust all over the barrel.