Rear shocks banging in mounts

[kyleag89]

I have a 2011 Sierra 1500 4x4 and have noticed a banging sound when going over medium and large sized bumps.  I have narrowed it down to the rear shocks but they are not blown.  I have Bilestein 5000 shocks on all 4 corners and have removed the rear two a couple times to inspect them.  Some googling led me to a couple people that had the same issue but no results in fixing it.  One guy suggested that it's the mounts or bushings but I don't see anything wrong with mine.  Has anyone else had this happen to them?

 

I wanted to add that I have the heavy duty leaf springs from the factory and they are in great shape.  I recently replaced the spring insulators with new ones and made sure the u bolts were tight.

Edited November 7, 2024 by kyleag89

[bubbanbrenda]

Did you check the spring eye bushings front and rear including the rear shackle bushings? 

[Jworks]

I have the same truck, same issue, but I've always attributed it to the leaf springs.  I put on new springs, was better (but not totally gone) for a while , now back like it was.  Same description as you, over medium or larger bumps like over uneven ground.  I sprayed the leaf spring bushings with WD40, silicone, that helps for a while then its back.  Dealer said I'd likely never get rid of it.  I think maybe he knew something.  Somewhere....somehow there is a fix for EVERYTHING.  But I've not found it.  Following

[kyleag89]

I did check the leaf spring bushings and shackles the noise is 100% coming from the shocks.  I have been investigating this noise for months and finally figured it out by driving on and off the curb in front of my house while a buddy kneeled down as close as possible to listen.  He pin pointed it to the rear shocks and sure enough if I hit the shock with the palm of my hand I can re create the noise!  To me it seems as if the bolts for the shocks that go through the shock bushings are too small.  With the shocks removed I put the bolts through the bushing sleeves and they have a lot of play.  I find it odd that this became an issue after driving 45k miles and there's nothing that looks wrong.  I don't want to replace Bilestein shocks that are still working to find out it didn't fix the noise.  I'm at the point where I might find something to insert inside the metal shock sleeve to close up the gap and insulate the metal to metal clang I'm hearing.  My first thought was to buy larger bolts that fit the sleeve better and drill out the holes on the truck to fit them but don't want to make an irreversible mod like that if not nessessary.

[64BAwagon]

Sounds like the bushings are worn out ?  Its a 13 yr old truck, many would consider something like that to be normal maintenance especially considering PA roads. 

[Jworks]

My noise is a croaking sound.  It sounds to me like something dry.  This may sound like a dumb question but I'm wondering this:  If I take the rear shocks off completely and drive over some uneven ground to see if the noise disappears will it hurt to drive it just a short distance just to test it ? 

Edited November 24, 2024 by Jworks

[richard wysong]

no it won't hurt anything.  creaking/croaking is usually ball joints, but that's not in the rear

[Jworks]

Richard, yeah its in the back. I'm not 100% sure but now I'm thinking its not the shocks.  I see no signs of leakage. From what I see in online videos this is a long standing issue with GM trucks.  I think I'm going to wait till after Thanksgiving and order some of those Spring-Things (rubber inserts).  I'll risk the $45 to get rid of this dry groaning sound. It really stinks that GM doesn't even care to offer a fix for this. 

Edited November 25, 2024 by Jworks

[Jworks]

In my case I solved the issue 100%.  Last week I received the Spring-Things I ordered.  I put them on myself and no more creaking, groaning, squeaking.  It was the leaf springs rubbing together.  I had some doubts but I gave it a chance and purchased the things.  I'm glad I did.  Noise gone.  This can be done cheaper at about half the cost by buying the 1/4"  rubber sheets on Amazon for about $19 and cutting out the inserts yourself.  If someone decides to do this I would recommend cutting them out in the shape as the ones at Spring-Things.com and tie them in with Zip ties.

[kyleag89]

Mine was the rear shock bolts.  I cranked them down with an impact and then finished them with a 24" long 1/2" breaker bar and they loosened themselves!  It was just the lower bolts on both sides.  I took them out cleaned the threads up and applied some blue loctite and cranked them back down.  It's been good now for a couple months.  About 6 months ago I had some noises from my leaves and I used an old wood chisel to seperate the ends and then put some new pads in there.  I had a few extra laying around from an add a leaf kit I purchased awhile ago because it was on clearance for $35!  Came with long leaves that fit under the main leaf, 4 leaf clips, 2 center pins, isolation pads, and 2 shims.  Not bad for $35.