I lowered the back end of my 2001 chevy silverado with DJM 2" lowering shackles in the back, now my leaf springs are squeaking badly all the time any ideas?

 

did the shackle's have polyurethane bushing's ,if so they can sometimes squeak like a bandit .also the bolt's that went into the bushing of the spring need to be never seized when installed .you are changing the traveling location of the existing wear points also check the clearance between the top of the shackle's and the bed floor for interference .