slow speed suspension clunking

sgt33356 · October 2, 2021

On 3/21/2020 at 5:04 PM, Gthompson said:

I'm having some issues with my brand new AT4. Just purchased a 2020 AT4 (2 weeks ago), had 24 miles on it. Within 100 miles it started making a clunking sound under the bed. Another 50, the steering started pulling and I had to take it in. Took it in and they tightened the u-bolts for the leaf springs which fixed most of the problem. The issue I still have is an annoying clunking sounds somewhere towards the middle of the truck, all the time. Happens at every stop sign, every turn, every speed bump. It's driving me crazy. The last time the dealer wouldn't even take it in. They said, "let us do some research before we bring it in." The suspension definitely doesn't feel like it did day 1, feels a lot "looser" and the clunking sound is tough to deal with.

Anyone having similar problems? Find a fix for it?

Thank you!

Just bought a 2021 Silverado, 2k on it and its clunking too!

Roy V · October 2, 2021

Update on mine. I haven’t done the grease on the springs yet, but, the past few days here in north NJ have been getting cooler in the morning ( 45- 50 degrees) and the clunking noise has vanished. No matter what I try to do to make it clunk, it’s not there. My guess is the rubber pads on the springs is harder and not grabbing the metal as they slide around.

sgt33356 · October 2, 2021

On 3/24/2020 at 8:48 PM, SRBOSST1 said:

Hey I just wanted to say please check out this other tread its seems these two should be put together.

This shouldn't be normal, I don't want a 50k clunky truck. Maybe we are all hearing the same thing but none of us nor the dealerships can figure it out. I can hear play in my rear axel as well by rocking the box side to side but that's not the noise I'm hearing in the cab while driving and if it is I will be very disappointed.

Yes I agree 100%, mine is a month old and clunking!

Roy V · October 2, 2021

My dealer changed spring packs on two trucks which made the noise go away for a few months but it slowly came back . Mine is a 2020 2500hd slt x31 grocery getter, did it since new, last winter it was almost nonexistent, this 100 degree summer people heard it as I drove by! Now it’s colder and it went away. The tsb says use grease but I think never seize or cavity wax for rust proofing cars wold last longer if it is the spring sliding on the pads.

Edgar_21 · January 13, 2022

My brand new LT does this too! what a disappointment! less than a month old, not even 500 miles yet. def not worth 50k.. took it to dealership and they re-torqued the u-bolt. still clunking on my way home...smh...

glad I found this thread tho... gonna try the spring thing route.

WeGone · January 13, 2022

41 minutes ago, Edgar_21 said:

My brand new LT does this too! what a disappointment! less than a month old, not even 500 miles yet. def not worth 50k.. took it to dealership and they re-torqued the u-bolt. still clunking on my way home...smh...

glad I found this thread tho... gonna try the spring thing route.

Mine finely stopped after 3000k miles and the spring thing. I used 2 sets one in front of the axle and one in the rear.

Roy V · January 13, 2022

25000 mi. and still no more noise. It went away in September when it started to get cold and the rubber pads stiffened up. We’ll see what happens when it warms up next spring and the pads get more grip to them . Also the rust proofing cavity wax is probably working it’s way in between the pads and springs.

ChevyJoe85 · January 22, 2022

I am now having a clunk on my brain new 2022 TB. So aggravating.

ChevyJoe85 · January 24, 2022

On 10/2/2021 at 8:12 AM, Roy V said:

My dealer changed spring packs on two trucks which made the noise go away for a few months but it slowly came back . Mine is a 2020 2500hd slt x31 grocery getter, did it since new, last winter it was almost nonexistent, this 100 degree summer people heard it as I drove by! Now it’s colder and it went away. The tsb says use grease but I think never seize or cavity wax for rust proofing cars wold last longer if it is the spring sliding on the pads.

I have a 2022 TB with the exact issues. Also installed a 1.5" RC leveling kit but I heard the clunk in the front prior to the leveling kit. Did you get it fixed ?

Roy V · January 24, 2022

Like my post said, it went away by itself when it got cold. The rubber pads stiffened up and slid on the leafs instead of chattering. …. If the leveling kit is for coil springs, I would say something is loose with the kit or maybe a shock mount isn’t tight enough. Torsion bar leveling kits only change the angle of the bar pre load bracket and should not cause any noise up front.

Edited January 24, 2022 by Roy V
Mis spell

Towbee · March 28, 2022

On 3/25/2020 at 11:46 AM, David Lampkins said:

I am having the same issues. I brought it in the dealership and they tightened bolts, however it was to no real avail. Let's get more people to chime in and maybe GMC will actually do something about this in a TSB...

I just Bought my 2022 Z71 LTZ same clunking noise I wonder if we can ho through the lemon Law on this ?

Roy V · March 28, 2022

Lemon law only works if it is a safety related issue and the dealer tried to fix it at least 3 times and failed to solve the problem…. Don’t let the monkeys at the dealership fumble with your $70,000 truck unless it’s absolutely necessary. The noise in mine hasn’t come back since it got cool outside and I sprayed some automotive rust preventive body cavity wax on the plastic leaf spring pads.

davester · March 28, 2022

Lemon laws vary with where you are located (from not having them at all, to covering most of the vehicle, for varying lengths of time). You need to research what they are for where you are located if you wish to persue a remedy using them.

poppy510 · April 12, 2022

OK fellas, I was 100% CONVINCED that the noise was due to excessive axle end play. Sounded like a tennis ball rolling around in the bed at low speeds, especially while turning. My plan was to have the dealer measure the lateral play when I got my first free oil change, but deep inside I know that this would be the first step in a shitstorm of BS from the dealer. I read all of the speculation about it being improperly torqued U-boats on the leaf springs, differential, shock mounts, bushings, calipers, etc. And the most implausible of all was the idea that the leaf springs were rubbing together and causing the clunk. But some of you sounded so believable! I'm a licensed mechanical engineer with a strong background in cars, boats, hotrods, customs, motorcycles, and I just couldn't wrap my head around how the leaf springs could result in that noise.

I decided to take a shot and buy the SpringThings recommended earlier in this thread. Took me 15 minutes to install and I'll be goddamned, but the clunking absolutely disappeared! While under there I could see that there is a LOT of force between those upper leaves, and when they slide (its a minute amount of motion), they "pop". It's not a smooth rub like you would imagine.

Anyway, thanks to all for the recommendation. $40 well spent...I'm in love again! PS I can no longer cause the sound by shaking the bed back and forth either. For those of you caught in the endless dealer loop, or paralyzed by multiple theories, do yourself a favor and cough up the $40...better than days at the dealer, and feels like a more robust solution than the TSB shenanigans.

brisk00 · April 13, 2022

On 4/11/2022 at 9:05 PM, poppy510 said:

OK fellas, I was 100% CONVINCED that the noise was due to excessive axle end play. Sounded like a tennis ball rolling around in the bed at low speeds, especially while turning. My plan was to have the dealer measure the lateral play when I got my first free oil change, but deep inside I know that this would be the first step in a shitstorm of BS from the dealer. I read all of the speculation about it being improperly torqued U-boats on the leaf springs, differential, shock mounts, bushings, calipers, etc. And the most implausible of all was the idea that the leaf springs were rubbing together and causing the clunk. But some of you sounded so believable! I'm a licensed mechanical engineer with a strong background in cars, boats, hotrods, customs, motorcycles, and I just couldn't wrap my head around how the leaf springs could result in that noise.

I decided to take a shot and buy the SpringThings recommended earlier in this thread. Took me 15 minutes to install and I'll be goddamned, but the clunking absolutely disappeared! While under there I could see that there is a LOT of force between those upper leaves, and when they slide (its a minute amount of motion), they "pop". It's not a smooth rub like you would imagine.

Anyway, thanks to all for the recommendation. $40 well spent...I'm in love again! PS I can no longer cause the sound by shaking the bed back and forth either. For those of you caught in the endless dealer loop, or paralyzed by multiple theories, do yourself a favor and cough up the $40...better than days at the dealer, and feels like a more robust solution than the TSB shenanigans.

I went to tackle this exact project this afternoon but the jack I have (non-gm) couldn't get the tire completely off the ground. I tried to wedge the springs with a flat head per instructions and they would not budge. I am assuming I need the tire completely off the ground. That being said I'll be trying the GM supplied jack tomorrow as I ran out of time today. So I have a question for you...

Per the Owners Manual it says to use the GM Jack on the axle between the differential and the shock. Is this what you did?