Upper control arm squeak

The noise drives me crazy, it creaks and squeaks even just sitting in the car. Looks like the prior owner put in polyurethane bushings. I lubed them once but the noise returns. Suggestions??

I have rubber up front everywhere. Poly only in the rear leaf bushings.

Your local building supplier will carry plumbers grease, which plumbers use to lube poly components in valves and fittings. That's what I used or I read somewhere that synthetic disc brake grease works well also but never tried it.

Jim