New member here with a doctorate in mechanical engineering. I have a vast knowledge of Jeep products and their charactoristic problems dating several decades back. One in particular is the squeaking serpentine belt. The "only" good solution I have found over the years beside barsoap, sprays and brake fluid is actually overtightening the belt. Yes, this sounds scary, concerning bearings and the such, but it has turned out to be the only answer. Do this with the engine running but be very cautious. If you are not an experienced mechanic, DO NOT attemp this procedure. Good luck, thanks, Dana.