leaf clunk

[Tmac Z71]

I've checked past posts on the stupid rear end clunk, and was wondering if there is a specific lubricant that seems to work on this issue. Should I just spray some wd40 in there?  Every turn and even backing out of the driveway is a noisy mess. My truck is a 17 and just recently has gotten bad. I took it to the dealership and the service manager printed me a bulletin and said its normal that the leaf springs pop and clunk. He also pushed on the bed back and forth and it popped like crazy.  thanks for any info.

[1SLOW1500]

Check bolts for right torque then added pads then other options are leaf spring clamps but they stiffen up the suspension. Unless you believe it is in the spring bushings then there are more options

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[ray2005]

The dealership said mine was fine but re-torqued the bolts anyway and mine stopped. I think they put some grease on the overload spring pad but that wasn't the issue.

When you install new u bolts they tell you to re-torque them after 500 miles or something.

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[Racindave]

1 hour ago, Tmac Z71 said:

I've checked past posts on the stupid rear end clunk, and was wondering if there is a specific lubricant that seems to work on this issue. Should I just spray some wd40 in there?  Every turn and even backing out of the driveway is a noisy mess. My truck is a 17 and just recently has gotten bad. I took it to the dealership and the service manager printed me a bulletin and said its normal that the leaf springs pop and clunk. He also pushed on the bed back and forth and it popped like crazy.  thanks for any info.

My dealer actually replaced the pads on my 18. Said it was a new improved style. They did look different to me. Dealer also greased the springs so it made me think the sound will come back later though. 

[Sierra Dan]

Some earlier threads and topics pointed to some sort of rubber inner tube repair between the spring layers.

[1SLOW1500]

Yes but honestly upgrade to a better rubber. It is like $10 or less on Ebay. Read rubber ratings first. I just bought a6 but on suspension I bought stiffer. Want to say it was d rated. Then pick your thickness and size. Want to say I bought 3" by 12" and cut it for the steal plate under my helper bags that sit on the leaf.

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[tyler.frost92]

dont spray wd-40 or grease on them, it will attract dirt and make the noise worse. Been there done that with all the bs at the dealer. Ended up getting all new leafs and the noises stopped.

[Jacoby]

Mine does the same thing and its annoying as hell.  Along with the clunk, mine have developed a creaking noise (like when you slowly open a door) and its driving me crazy

 

Anybody know the torque for the ubolts back there?  Mine had a lift installed when I bought it and that was 10K miles ago.  Probably need to be retorqued

[1SLOW1500]

Mine does the same thing and its annoying as hell.  Along with the clunk, mine have developed a creaking noise (like when you slowly open a door) and its driving me crazy
 
Anybody know the torque for the ubolts back there?  Mine had a lift installed when I bought it and that was 10K miles ago.  Probably need to be retorqued

Well gm says that you need new bolts as they are one time use. I recommend buying aftermarket harden u bolts and nuts. Then you can reuse and torque down more.

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[LDM]

I just dealt with this on my 2015 Sierra, it kept getting worse since the winter.  Every time I went in or out of my driveway it sounded like my entire rear end was banging around.  Tried tightening the u bolts and lubricating the pads for the springs, it helped for a bit and then came back even worse.  A couple weeks ago I got some gasket rubber from the plumbing department at my local Menards and cut that to the width of the springs and put it between them.  Absolutely no clunking noise anymore.  Cheap and easy fix although I'm not sure why GM can't bother to put good pads on their leaf springs.

[Jacoby]

32 minutes ago, 1SLOW1500 said:

Well gm says that you need new bolts as they are one time use. I recommend buying aftermarket harden u bolts and nuts. Then you can reuse and torque down more.

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The u bolts I have are aftermarket, they came with the lift. 

[tyler.frost92]

47 minutes ago, Jacoby said:

Anybody know the torque for the ubolts back there?  Mine had a lift installed when I bought it and that was 10K miles ago.  Probably need to be retorqued

1/4 turn before they break 

[1SLOW1500]

I was going to say 140ftlb but that isn't right that is the lug nut spec. I say 170 will hold I use my air gun then come back with my Snap On Brutus torque wrench. Then check them after a few hundred miles.

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[reardiff]

5 hours ago, LDM said:

I just dealt with this on my 2015 Sierra, it kept getting worse since the winter.  Every time I went in or out of my driveway it sounded like my entire rear end was banging around.  Tried tightening the u bolts and lubricating the pads for the springs, it helped for a bit and then came back even worse.  A couple weeks ago I got some gasket rubber from the plumbing department at my local Menards and cut that to the width of the springs and put it between them.  Absolutely no clunking noise anymore.  Cheap and easy fix although I'm not sure why GM can't bother to put good pads on their leaf springs.

 

Mines doing the exact same thing. Happen to have any pics of your gasket fix?

[ray2005]

I've seen a few references for torque specs and this is what I saved

 

Rear U-Bolts: first pass 59 ft.lbs, second pass 130

 

 

https://www.gm-trucks.com/forums/topic/189862-u-bolt-tightening/#comment-1839587

 

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