noise in the back

I have been working on this since I have gotten the lift on the jeep. I have tightened the bolts on my lift any times. I know everything is tight, but it seems like when ever my jeep gets wet, there is a bang in the back end. It's not a big loud bang, it just sounds like something is loose and moving around. When I first heard this noise I tightened the U-bolts that hold the rear springs in place, and the first couple of times they were loose. I got tired of it, and put Lock-tight on the U-bolts(the blue kind). They were the only thing that was even a little loose. But I'm still getting the bang when the Jeep gets wet. Is it possible to have the springs get wet and then move just enough to make a banging noise when they move? It is the only answer I can come up with.
It's a 2001 with the RE 3.5 superflex and full leaf packs. Any ideas?

exaust pipe hanger might be busted

Do you hear it whenever you hit a bump, or when going around turns? I ask this because I have a noise coming from the back that seems to be suspension related. I mainly hear it going around tight turns, and out on the trails.

I only hear it when going around turns, I haven't heard it much on the trails. It seems like I only hear it when the weight on the body shifts. Sometimes when I'm going over small dips in the road, not bumps just where the road dips down. The other thing is I only hear it when the Jeep is wet or the day after. The exaust hanger isn't loose, like I said in the first post I have tightened everything that has a bolt.

Hey guys I know what ur talkin about, I hear a clunk in the back of mine every time I hit the gas or around a turn. Check ur shackles and see if they are bent in any way. Also go back there get underneath and push up on the shackle and see if u hear the same noise. Sometimes after flexing around a alot U could tweak your mount or push the leaf spring over and it will hit the side of the shackle. Also grease it up using the zerk fittings and lube ur bushings with some liquid wrench. If all else fails lossen ur bolt to ur leaf on the shackle a bit because they tend to tighten alot over time. hope u find the problem becease it can be annoying. Just for info I also have and RE 5.5 long arm kit.

I'll try that but why do I only hear it when the Jeep is wet? Could water get in between the leafs themselves? Then when the leafs move around while driving, they make a noise?

U have to reallly get underneath and check it for the noise as someone puhes the jeep up and down or side to side and find whats making the noise. And stuff always makes noise for a little while after it hasnt been greased for awhile becase water slowly melts grease away and has a tendecy to get crud and rocks that cause unwanted squeeks and clunks. Try fishing around and tell me what happens.

as you drive your Jeep don't the leafs move back and forth on each other? I was thinking that the leafs are moving back and forth against each other and that is what is making the noise. When they are dry they don't make noise but when they are wet they do. Could that be the problem? I have checked and rechecked and everything seems to be tight. I had heard once that if you re-paint your springs you should use graphite paint for the lubrication. Could it be that when RE painted these they didn't get enough paint on the springs? It rained last night so right now they are making all types of noise!

all you guys that have lifts and no one can tell me about leaf springs and if they move while you drive? come on guys I need to know if this something I should be worried about or if it's no big deal.

yes, the leaf springs slide against each other when the rear axle moves.

so it is possible that there is nothing wrong with the lift or Jeep, and the leafs are just, when there are wet, making noise as they move back and forth. If so then this is something that I don't really need to worry about?