Dogdad

It’s the leaf springs.. their lpkastic grey bushings suck. Install the Spring things.. easy fix and solves it. Read my earlier posts.

Get the rubber spring things.. it’s your leaf springs . Read the upper posts. These are rubber bushings that separates the two leafs making the sound. It’s a known widespread issue.

Great to hear! How do you report it to GM?

It’s 1/4” thick. You can buy a 1/4” 12 x12 sheet on Amazon for $21 also

Radio is playing but screen is blank. Try to get to the Home Screen and nothing. Any idea or fix for this? 2021 SLT

Check out my last post. Installed the Spring thing kit. No more clunking sounds finally!!

Installed the “SPRING THING “ KIT. Works great. No more clunking sound. Spring-thing.com. Here’s a pic of them installed on my 21 Sierra . Spring-things.com

Ok…bought the “Spring Thing” rubber spacer kit. I don’t have a jack or jack stands so I had my dealership install them . They work fantastic. No more noise at all. The shop foreman actually did it for me. He said their dealership actually had been putting rubber bushings they made a couple of years ago and it solved everyone’s clumping noise. However, GMC came down on them and said to quit doing it and they stopped paying the dealership for the install. GMC is putting these cheap plastic spacers in that don’t work. He said it’s only a bandaid fix. So, I recommend these rubber SPRING THING. Easy install . There’s a video on their website showing it. Here’s mine installed. 01B7052E-9ADC-4C47-8405-AC6EF91E6CC8.webp E4D40E3F-1B40-4338-870F-BCFF257645BA.webp 995B9B4D-295C-410A-A78B-D2582D49DF90.webp

Sorry for a dumb question, but do you have to undo bolts to slip in this rubber piece? I just had the leaf springs replaced on my new 21 Sierra with 300 miles on it and still have the clunking noise. Looking today I see the inserts are indeed plastic on the new springs .

Well, it didn’t last long. Thumping noise is back as before after new leaf springs installed. This is a problem that GMC needs to get resolved.

They did today. No more thumping noise. Took about 2 hours.

Did you see the post above with GM bulletin notice in regards to this. The shop foreman at my dealership will be working on mine himself and said just replacing the bushings does not fix the issue. So he ordered the whole package to replace mine. Tuesday is the lucky day to get fixed.

My truck is finally going in next week for leaf spring replacements. There is also a bulletin out on this matter..

Evidently it’s not bushings, but they are replacing the entire leaf springs.

The thumping noise I hear is when I go over a bumpy road or driveway curbs at a slow speed. Coming from the back of the truck.

Found out today that the thumping noise is indeed the leaf springs. Took a whopping 10 seconds of riding with a service manager for him to know what it was. They wrote up a ticket, ordered the springs, and will call me when they come in. The guy was great and professional. He said they are seeing issues with the new trucks and the whole leaf spring has to be replaced.

So, I believe I have discovered what the mystery thump noise in the rear is. Talking to an ex Chevrolet service manager of several years that now owns his own mechanic shop enlightened me of the issue. The shaking of the truck side to side indeed creates a sound, but it’s not what we’re hearing. Shaking the truck sideways creates the axle play sound which they all have and is normal. . What we’re hearing is the leaf springs. I’m told that GMC has a kit to replace the leaf spring bushings . They are aware of this. I’m actually going to my dealer tomorrow morning to discuss this with the service manager there. I’ll post my outcome.

Please post what you find.

So bought the truck last week and noticing a slight noise like thump thump from the back end . It can be clearly heard when going on the street curb of a driveway . Couldn’t figure it out. This morning a friend and I finally shook the rear tires and it produced the sound. Thought I had a loose tire. So I went to the dealership and of course they couldn’t see it right away and I couldn’t leave it. So I’m going back to my truck and stop to tell a tech. He comes over, shakes the tire and said wow. Thought it might be the spring. Then he and I go and shake the tires of two other brand new trucks. They all made the same noise. Just doesn’t sound right. Any idea on where it’s coming from?

I see there have been discussions on the CarPlay issue, but has anyone heard or come across a fix or upgrade for this? Just purchased a new 2021 Sierra $55k and find this issue ridiculous. When it works it’s fabulous with the Bose speakers, but when it skips, I’m cursing. ..

Just picked up my 2021 last week and heard about the leak problem afterwards. I have the power sliding window. If it leaks I’ll deal with it then, but I’m also going to put a small strip of newspaper under the window as newspaper is a good material showing water if water has gotten in.

I read about it, but personally wouldn’t want it or trust it. If sensor fails for any reason, there goes the tailgate. Jmo

Look up B&W trailer hitches...

What hitch are you using so your multipro tailgate doesn’t hit when lowered?

Any word on whether the 2021’s are having this leak issue?