lifted06gmc

I have determined on my 06 GMC Sierra 4x4 that the rear leaf springs were the problem. I ended up loosening up the u bolts holding the leafs together to where the leafs had plenty of gap in them and i sprayed a teflon lube between each leaf. I then changed out the u bolts with new ones also new shackle bolts and bushing and tightened it all back down. The truck hasn't made a popping noise since. It has been almost a year since i done this work.