I recently diagnosed a squeak in the rear as a bad shackle while in the dark in a wet parking lot with the aid of a flashlight. Today got it on the lift and am having second thoughts. Originally I noticed that the bolt that attached the shackle to the spring was rubbing on the frame. I thought at first that the shackle had gone bad but today when I got the weight off the springs I noted the shackle seemed fine. The springs look worn and I'm wondering If worn springs are causing the shackle to roll and rub the frame. I don't have much experience diagnosing suspension problems. Any guidance would be greatly appreciated