squeaking and creaking, I have had the same issue, I just put a squirt of wd40 on the both ends of weight distribution bars (I have the dual cam) and it seemed to work. Still get the clunks every once in awhile. If you can try a short tow without the WDH to see if still squeaks and creaks...
So basically No squeaks, No creaks, but still have the clunks.
This is starting to sounds like "Space Balls" the movie, does anybody remember the scene I am referring too?
2012 Freedom Express Liberty Edition 292BHDS
2011 GMC Yukon XL 2500 4X4 (what a difference)
2007 Ford Expedition EL Eddie Bauer 2WD (sold)