WD-40 is never OK to use as a lubricant. WD stands for "water displacing" and its main use is as a solvent or rust dissolver. The lubricant-like properties of WD-40 come not from the substance itself, but from the dissolving components in it.

Use some actual grease. Lithium grease would be great.

 

Thank you for the education, Jabber! I did not know about any of that. I only did a quick Google check to compare WD-40, silicone grease, and lithium grease at the auto parts store and there was some mention of lithium should only be used with metals and not plastics so I went with the silicone grease but ended up not using any of it. I was going to apply some to the struts and then saw they came pre-lubed. Thank you again for taking the time to steer me in the right direction, much appreciated.