slow speed suspension clunking

SherryAT4 · August 10, 2021

On 3/24/2020 at 8:02 PM, Gthompson said:

Thanks, Shawn Fox. That’s interesting, going to jump into that conversation. I thought the same thing, I definitely don’t want a clunky 50+K truck. That’s insane to me. Also, considering I just traded a 2019 Trail Boss, which I would guess has the same rear diff with no clunking sound, it’s hard to believe. I’m going to post on the other thread as well. I hope this is the issue and it can be fixed, can’t imagine keeping this truck for long with it banging around from even pulling into a gas station.

Also, good point about the play in the rear axle when you push on the side. I checked a brand new Denali, my old Trail Boss (that's sitting on the lot for sale), a used AT4 and a brand new AT4. They all do that, but I know my old truck didn't make this particular noise.

Help my 2020 AT4 6.2 - (my truck has the AT4 2 inch lift plus an additional 5 inch lift ) is making all sorts of dang noises . I have taken it to a local dealership twice and they can’t hear anything . Every time they have it it sounds worse ! I am a female I don’t know how to explain the noises . When I start it I hear a damn chirp . Then as I am going 40mph I hear a sound that sounds like a marble inside a empty Coke can . I hear it so often I want to drive the truck off a cliff. The dealer (out of state ) that I bought the truck from put the lift on. It’s also a Carbon Pro .if that matters. As I am driving I often hear a clunk - in my definition it sounds like the damn motor just fell out . Driving up a mountain sounds and feels like my truck doesn’t have enough power . I think it struggles . As I am going up a steep incline I hear that dang marble in the Coke can noise .
Pulling up to a stop light I hear it . This is getting old . $75k and it sounds like a dang hoopty. It has 8200 miles

yes - it was brand new - they had to put 500 miles on it first because of the lift before I could drive it back to my state .
I have had it at the local dealership twice .. 4 people drove it . They all hear nothing ! I am so pissed off. This sucks because I have no clue where the noise is coming from - I say it’s the engine . I hear it when I am driving . I can hear it when the AC is on . When the radio is playing ... but no one else seems to hear it . I hear it when I am

on the passenger side . I don’t hear it as much when I sit in the back . I didn’t start hearing the Coke can noise until 4800 miles . Chirping noise I heard it around 1000 miles . The clunk noise is new after the dealership probably screwed it up more when I took it in for them to hear the Coke can noise . Can anyone help .

Edited August 10, 2021 by SherryAT4

KevChev · August 10, 2021

Hey all -

So I just got my SpringThings in the mail today (Monday) but, I swear, the clunking has magically gone away in the last 3-5 days. Now, it has been pretty wet here the last few days (major rain storms) so maybe the moisture has something to do with it (maybe acting like a pseudo lubricant?) but I've driven quite a bit since last week Wednesday when I initially posted and I cannot hear/feel the clunking anymore coming from the leaf springs.

That being said, I will not be installing the SpringThings until I hear the clunking come back (if it ever does). Could this honestly be a "breaking in" of the new truck? Again, I bought the truck brand new off the lot and it now has 500 miles on it. Either way, I'll take it. It's nice knowing I have the right parts if the clunking should come back.

Dogdad · August 10, 2021

3 minutes ago, KevChev said:

Hey all -

So I just got my SpringThings in the mail today (Monday) but, I swear, the clunking has magically gone away in the last 3-5 days. Now, it has been pretty wet here the last few days (major rain storms) so maybe the moisture has something to do with it (maybe acting like a pseudo lubricant?) but I've driven quite a bit since last week Wednesday when I initially posted and I cannot hear/feel the clunking anymore coming from the leaf springs.

That being said, I will not be installing the SpringThings until I hear the clunking come back (if it ever does). Could this honestly be a "breaking in" of the new truck? Again, I bought the truck brand new off the lot and it now has 500 miles on it. Either way, I'll take it. It's nice knowing I have the right parts if the clunking should come back.

I’m willing to bet you get the return of the clunk…mine went away with new leaf springs installed..but came back with in a week..

KevChev · August 10, 2021

Yea I've basically been waiting for it to come back the last few days...like I said, at least I'll be ready for it if/when it does return. I was kinda looking forward to doing a little tinkering on the truck too, but I guess I have to take my good fortune, even if temporary, for what it's worth.

Duramax2021 · August 20, 2021

I Hope this isnt a stupid question but when you add these rubber isolators to the leaf pack, does this change the amount if weight you can put in the back of the bed. i know the more weight you add in the bed the more the leafs compress. if you add these isolators does it not allow for the full compression

davester · August 20, 2021

No, they don't alter the weight rating of the truck. The only difference would be, for the same load, the rear of the truck might ride slightly higher.

Duramax2021 · August 20, 2021

thanks!

JPN · September 7, 2021

I installed the spring thing and the it did not help, still have the clunking noise. It did rain the other day and noticed that when the springs are wet the there is no clunking.

WeGone · September 8, 2021

Just wanted to update this.

I installed TheSpringThings July 2nd at the time I had about 500 miles on my Z71. They worked great completely stopped the noise.

Now I'm at 2700 miles and it has returned. Good thing is its not as pronounced or lets say a more subdued muffled sound.

Backyard tech · September 11, 2021

Hi Newbie here.

My mother in law recently purchased a low mileage 2019 silverado.

I noticed a clunk as she pulled in my stone driveway.

Apon checking with the right rear wheel on and pushing in and pulling it back.

I felt alot of end play and heard the clunk in the axle.So much that I even saw the rotor move with the wheel.

Also checked the left side low an behold same amount of excess end play.

Headed to the dealer this week.

I see alot of posts on this issue here.

I am not a gm tech or owner.

But it appears from my inspection this is an issue in the rear differential axle end play.

Hope this may help others with the same issue

swathdiver · September 12, 2021

On 8/9/2021 at 10:36 PM, SherryAT4 said:

Help my 2020 AT4 6.2 - Then as I am going 40mph I hear a sound that sounds like a marble inside a empty Coke can . I hear it so often I want to drive the truck off a cliff. ...in my definition it sounds like the damn motor just fell out . Driving up a mountain sounds and feels like my truck doesn’t have enough power . I think it struggles . As I am going up a steep incline I hear that dang marble in the Coke can noise .

What kind of gasoline are you using in this truck?

Roy V · September 12, 2021

My 2020 2500hd is doing the same thing when going over bumps like when going over a speed bump on an angle. Thought it was the spare or something above it. If you get the truck rocking from side to side by pushing on the side of the bumper ( you really have to get the sidewalls of the tires flexing)it will make the noise. (It’s not the axel end play click, it’s a deep, inside the rear clunk.)When lying under the back of the truck while someone rocks it side to side, it feels and sounds like it is coming from inside the rear. I have 17568 mi on it. It made the noise a little when new but is getting worse after 1 year of driving.This truck has never hauled or towed anything.

jennifer fox · September 17, 2021

On 3/23/2020 at 11:40 AM, Chad's Trail Boss said:

My stealer looked at mine last week and said the inserts were the correct ones.
Said they cleaned between the leafs real good and it fixed the problem.
This weekend the problem returned.
I have Air Lift bags on the rear of my truck and they are giving me hell saying the bags are causing this issue.
I’ve added lots of air, taken all the air out, and had the pressure up to about 12 psi and various ranges in between and it will still squeak.
Every damn time I bring it in it’s not hardly doing it. I’ve found when it rains or there’s just a lot of moisture in the air, the springs tend to not squeak or not squeak that bad. I keep videoing when it’s bad but I guess that’s not good enough for them.
I’m sick of dealing with this ****** and ready to just fix the ****** myself.
They say I’ve technically voided my warranty because I’ve modified the rear suspension. SMDH
Screw it. I might as well go ahead and lift it more now.
My rear brakes keep squealing intermittently too and I’ve have videos of that as well.

I'm about done with my dealership as well. I'm capable of doing my own repairs within reason. I'm learning everyday. They have cost me over $2000 on unnecessary repairs and gave me crap about a recall fix I needed. I mean seriously? It's a recall! I put a 2.5 leveling kit on and apparently that causes every issue I have including recall ones. My warranty ran out a long time ago.

Roy V · September 18, 2021

Dealer just told me they had two others come in for the same thing. One truck had the spring pack replaced and the noise came right back so their trying it again. The other one is coming in for the first spring change. Service advisor and the tech both said to me that this is not a fix for the problem and I agreed that changing the springs is a disservice to the vehicle. We talked about how grease is not to be used on leaf springs ever. Even though the TSB says to grease the pads between the spring pads. He said my idea of dry lube with Teflon or anti seize or molybdenum would be a better choice and last longer and not collect dirt like grease. I’ll post the results after I do it. If the noise goes away, I’ll know it’s not inside the rear.

gerry · September 23, 2021

I have a 2021 Sierra 1500 SLT with the X31 package and Z71 off road suspension. It has 700 miles on it. The clunk is like many descriptions here, lateral over a speed bump at 3 mph and its clunk, clunk. It does sound like the spare tire is loose.... good analogy.

Local dealer says leave it for a couple of days and they see if they can diagnose it.

TSB 19-NA-129 is the requisite TSB for this.

https://static.nhtsa.gov/odi/tsbs/2020/MC-10174269-9999.pdf