LHC

Hi Guys,
I recently completed installing Racers Edge derlin outer spring
plate bushings. It ran o.k for a couple of days & than it started
to squeak. Prior to the purchase, I was informed that it would
not squeak. I also added some teflon grase during the install.
I've read that some of you are using this bushings without any
problems. Can someone shed some light on this please.
Could I have made a mistake during the install ?