Polyurethane bushing manufacturers advise to never use a petroleum based grease for poly bushing lubrication. Polyurethane should only be lubricated with one specific type of grease to insure long bushing life, and squeak-free performance, Silicone based synthetic water-proof grease.
We've found this grease to be so good, we use it for the entire chassis lubrication on the cars we build and race out of our shop. It stays where you put it and doesn't wash away. This grease can be very hard to find at your local stores. This grease is available from Spohn Performance, it's our Part #902, click here to check it out.
