I had a bad leaf spring squeak that has been driving me crazy for the last 10,000 miles. I never knew if it was a factory issue or from the add a leaf I added when I first picked up the truck. Had time today to go to the spring shop. The end of the add a leaf was rubbing the next leaf down just enough to squeak. I had tried to lube, grease, wash, silicone several times and could make it go away sometimes but did not know where the lube fixed it. Spring shop added plastic circular pads to the end of the add a leaf and used a strong epoxy to hold them to the leaf. They were about 1/8 inch thick and 3" round. Immediately no more squeaking. The squeak was getting as loud as an old screen door spring noise until now.