...nut or whatever they're installed to maintain pressure on. I can't recall their name. Just a thought. What about shooting some white lithium grease in there, reassembly to the extent you can tell if it still squeaks. Sort of a test run? Not sure what's possible. Look at the link, the 'bent washer'.

http://www.grainger.com/product/22RJ42?gclid=CMGngLzJqckCFUiFfgodi8UAlw&cm_mmc=PPC:GOOGLEPLAA-_-Hardware-_-Springs-_-22RJ42&AL!2966!3!50916710997!!!g!82128738957!&ef_id=ViXR9AAAAcRBOMfl:20151124172253:s