Rear window leak

RadBrad · November 13, 2020

4 minutes ago, Z71RAD88 said:

Well, there goes that. I was hoping the 21's would be fixed.

Yup, My guess is if it is not fixed in the 2022 redesign, it probably wont be fixed until a complete remodel. Maybe GM actually has tried to fix, and cannot fix it...like someone else mentioned, the GM Shake, the brake vacuum pumps, the air conditioning condensers etc. of the 2014-2018 models...

Edited November 13, 2020 by RadBrad
Missed word

Z71RAD88 · November 13, 2020

7 minutes ago, RadBrad said:

Yup, My guess is if it is not fixed in the 2022 redesign, it probably wont be fixed until a complete remodel. Maybe GM actually has tried to fix, and cannot fix it...like someone else mentioned, the GM Shake, the brake vacuum pumps, the air conditioning condensers etc. of the 2014-2018 models...

I think someone else here made a hint that it's body flex causing the leak as GM took too much "meat" out of the cab to make it as light as possible, which if you look at the HD models, very few ( I think one member) had the leaking window issue. But it doesn't seem to be nearly as widespread on the HD trucks.

Well, I'm glad I wasn't overly aggressive in pursuing a 2021. I guess I'll have to look at Ridgelines now. Ha ha...never.

RadBrad · November 13, 2020

7 minutes ago, Z71RAD88 said:

I think someone else here made a hint that it's body flex causing the leak as GM took too much "meat" out of the cab to make it as light as possible, which if you look at the HD models, very few ( I think one member) had the leaking window issue. But it doesn't seem to be nearly as widespread on the HD trucks.

Well, I'm glad I wasn't overly aggressive in pursuing a 2021. I guess I'll have to look at Ridgelines now. Ha ha...never.

Yea that does make sense, I think the silly spoiler could have something to do with it as well...we might not ever really find out lol

OnTheReel · November 13, 2020

I just think it has to be a deeper problem. If it’s only a bad window design (as GM initially thought almost 2 years ago), the revisions would have fixed it if it was fixable. But as we see, making the plastic frame thicker and whatever else they have supposedly tried does nothing if the cab around it is twisting / flexing on bumps. The window frame is still the weak link and would break no matter what.

I think this flex issue also coincides with the “popping” roof thing that some people complain of, as well as the reviews from car mags who have beaten up on these trucks for having a “noodle-y” structure.

From Car & Driver:

Our frustration with the Silverado is rooted in its ride and the noodly feel of the structure. Chevy followed its crosstown rival down the aluminum road only a short way, stamping the hood, doors, and tailgate from aluminum. The body and box are still steel. Chevy manages to undercut the Ford by 90 pounds just the same, though after driving the Silverado, we wished Chevy had put a little more beef into its structure. Those 22-inch wheels are the hammers, and the body is a dulcimer string. This truck shakes and vibrates so much that, bombing down a rough road, we expected to get a call from OnStar asking if we'd been in an accident.

HDs are fairing a lot better which makes sense since they weren’t designed with only light weight and fuel economy in mind.

And of course the fixed rear windows don’t leak because they use one solid piece of glass that actually adds some stability to the cab. Just as the windshield is considered a part of the structure.

Not hard to connect the dots.

Z71RAD88 · November 13, 2020

3 minutes ago, OnTheReel said:

I just think it has to be a deeper problem. If it’s only a bad window design (as GM initially thought almost 2 years ago), the revisions would have fixed it if it was fixable. But as we see, making the plastic frame thicker and whatever else they have supposedly tried does nothing if the cab around it is twisting / flexing on bumps. The window frame is still the weak link and would break no matter what.

I think this flex issue also coincides with the “popping” roof thing that some people complain of, as well as the reviews from car mags who have beaten up on these trucks for having a “noodle-y” structure.

From Car & Driver:

Our frustration with the Silverado is rooted in its ride and the noodly feel of the structure. Chevy followed its crosstown rival down the aluminum road only a short way, stamping the hood, doors, and tailgate from aluminum. The body and box are still steel. Chevy manages to undercut the Ford by 90 pounds just the same, though after driving the Silverado, we wished Chevy had put a little more beef into its structure. Those 22-inch wheels are the hammers, and the body is a dulcimer string. This truck shakes and vibrates so much that, bombing down a rough road, we expected to get a call from OnStar asking if we'd been in an accident.

HDs are fairing a lot better which makes sense since they weren’t designed with only light weight and fuel economy in mind.

And of course the fixed rear windows don’t leak because they use one solid piece of glass that actually adds some stability to the cab. Just as the windshield is considered a part of the structure.

Not hard to connect the dots.

Yup. Well said.

RadBrad · November 13, 2020

3 minutes ago, OnTheReel said:

I just think it has to be a deeper problem. If it’s only a bad window design (as GM initially thought almost 2 years ago), the revisions would have fixed it if it was fixable. But as we see, making the plastic frame thicker and whatever else they have supposedly tried does nothing if the cab around it is twisting / flexing on bumps. The window frame is still the weak link and would break no matter what.

I think this flex issue also coincides with the “popping” roof thing that some people complain of, as well as the reviews from car mags who have beaten up on these trucks for having a “noodle-y” structure.

From Car & Driver:

Our frustration with the Silverado is rooted in its ride and the noodly feel of the structure. Chevy followed its crosstown rival down the aluminum road only a short way, stamping the hood, doors, and tailgate from aluminum. The body and box are still steel. Chevy manages to undercut the Ford by 90 pounds just the same, though after driving the Silverado, we wished Chevy had put a little more beef into its structure. Those 22-inch wheels are the hammers, and the body is a dulcimer string. This truck shakes and vibrates so much that, bombing down a rough road, we expected to get a call from OnStar asking if we'd been in an accident.

HDs are fairing a lot better which makes sense since they weren’t designed with only light weight and fuel economy in mind.

And of course the fixed rear windows don’t leak because they use one solid piece of glass that actually adds some stability to the cab. Just as the windshield is considered a part of the structure.

Not hard to connect the dots.

Totally agree with all of that...my 2016 and 2018 felt much connected to the road over rough surfaces. These new models do feel like they are jumpy over any type of bumps. Thanks for the C&D impression.

econometrics · November 13, 2020

2 hours ago, RadBrad said:

Totally agree with all of that...my 2016 and 2018 felt much connected to the road over rough surfaces. These new models do feel like they are jumpy over any type of bumps. Thanks for the C&D impression.

I didn't own a K2, but I can tell you the T1 is about as planted of a vehicle as I've driven. The jumpiness that C&D describes has everything to do with the CRAP shocks that GM puts on these trucks. Swap them out, and you'll experience an incredibly better handling machine.

Anyway... not at all surprised that the 2021's are leaking. There have been ZERO substantive changes on these trucks. As someone above said, if this is not solved for 2022, we will have to endure it until the next platform redesign... probably in 2025 or something.

OnTheReel · November 13, 2020

The poor ride definitely exacerbated the flex in the structure, at least in the eyes of that reviewer. But it’s still two separate issues.

Personally, I do not think my 19 is that bad. The max trailering package and Bilsteins really help. Also, GM did use new springs for the 2020MY to address some of the ride issues.

My ‘16 still felt more secure over rough crossings and didn’t have that rattling feeling throughout the cabin. It was probably close to the same weight as my 19 since it had less options. But it felt much heavier and more solid.

paui4m · November 14, 2020

Got mine back tonight after 24hrs of adhesive curing and a new window seal.

It was allegedly run through multiple water tests and no leaking so we'll see how long it lasts.

Truck was definitely soaked when I picked it up.

If it recurs, I am pursuing the solid rear window path.

On a more positive note my Lomax cover arrived today and I get to install that this weekend.....

DSW1519 · November 14, 2020

My 21is built and being shipped now. Bummed to see this is still an issue with the 21s. I'm going to try the weather strip as jrodpic suggested and hope that will be enough to prevent leaks. Honestly when mine starts leaking I think I will go the solid window route and just be done with it. Disappointing gm hasn't resolved this yet

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Palytoxin · November 14, 2020

Glad I double checked this thread. I have been looking at a 21 Sierra 1500 AT4, but I am going to pass for now. Can't stomach the thought of buying something with known leaking issues, especially for this price.

Cpl_Punishment · November 14, 2020

20 hours ago, RadBrad said:

Yup, My guess is if it is not fixed in the 2022 redesign, it probably wont be fixed until a complete remodel. Maybe GM actually has tried to fix, and cannot fix it...like someone else mentioned, the GM Shake, the brake vacuum pumps, the air conditioning condensers etc. of the 2014-2018 models...

My thoughts exactly. I suspect they're going to have to redesign the whole rear end of the cab to try to come up with something where the window frame won't be susceptible to cracking.

Duramaxsky · November 14, 2020

I have been checking mine every rain. Everything from mist to heavy rain. No leaks. I have the longer cab. It seems these are all the shorter crew cab. Is that correct? Maybe a difference in how they flex?

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Blue5.3l · November 14, 2020

Can you order a higher model truck with a slider delete?

Blue5.3l · November 14, 2020

If you switched to a solid window from a slider is it still a possibility to have rear defrost? Safelite shows it would be around $400 to have a tinted solid window with defrost installed. I would imagine all would be needed is to pull the fuse for the slider function to not work.