Does petroleum based grease eat up polyurethane bushings?

[rushdunaway]

I sprayed some WD 40 on my polyurethane leaf spring bushings, and they started squeaking and creaking. It has now gotten a lot worse and sounds like the suspension is going to fall apart whenever I hit a bump. I have heard now that petroleum based greases can eat up polyurethane, but isn't polyurethane made from petroleum?

 

[rockcity]

yeah, you should keep that stuff away from poly bushings

 

[AlphaFourWheelDrive]

Use a silicon based grease. 3M Silicon paste is nice.