Rear window leak making me rethink a new truck.

GN2018 · March 22, 2021

I have a GMC Denali tagged. As of this moment, I have no obligation to buy it, but I’m that close. I’d be trading in my 2018 Silverado. My Silverado is an LT, so my main reason for buying is an upgrade in comfort and ride handling. However, the more I read about the rear window leak, the more I think I should just keep my 2018. If had no problems at all with my 2018. I feel like the rear window leak is so pervasive that I’d be trading a good truck for a bad one. I can imagine after a few years seeing these trucks with rust around the back window. It also seems like a problem that will always be there - can anyone say extended warranty?

Am I over reacting? Having got this far, I’m sure you can imagine that I really want this truck. Difference over trade it is $20K+. Spending that on a truck with a problem seems foolish.

andrewb24 · March 22, 2021

There are lots of people not having any problems with the rear window. If you like the truck buy it. Thats my opinion.

GN2018 · March 22, 2021

29 minutes ago, andrewb24 said:

There are lots of people not having any problems with the rear window. If you like the truck buy it. Thats my opinion.

I guess I’m worried that they’re “not having any problems” that they’re aware of. Seems like if there is a design flaw, it’s just a matter of time before it rears its ugly head. Like maybe at 37 months or 37K miles. Not sure how to rule that out.

OnTheReel · March 22, 2021

Doesn’t sound like you need a new truck right this minute so I would say wait. Not only to see if something is done with the window leak for 2022, but because we are so close to the refresh coming out. These are nicer trucks than the K2s in many ways, but there’s still no sense spending 20k to upgrade to a lame duck.

gmcsierra71 · March 22, 2021

Your concerns is why I posted this a few days ago:

econometrics · March 22, 2021

I have a 2019 RST that's been leaking since fall of 2019. Dealer did the first re-seal, and then I've just been living with the small dripping ever since. To be honest, it isn't that big of an issue to me anymore. I do realize, however, that some owners have had much worse leaks - making the cabin smell moldy, staining the headliner, etc.

As OnTheReel said, I would just at least wait to see what the 2022 refreshes look like, since we'll know in a few months.

DSW1519 · March 22, 2021

GN2018 - I truly understand your concerns and was in your position last fall.

I ordered a 21 and took delivery in December 2020. I ordered the truck being aware of the leaking slider issue, and because I liked the truck so much (and despised my 18 F150 so much) that it was worth the gamble. I also decided that if the slider became a continued issue I would pay the cost of swapping for a non-sliding window - and knew that was a possibility from the start.

Ten days into ownership the rear slider started leaking. Dealer performed the TSB and sealed the slider top gap. It was good until mid February, where I notice a slight drip after days of rain. It was a small enough leak that the towel I have on the rear seat back wasn't wet to the touch. Once we had a warm day I put a layer of flowable silicone on the top of the window gap - see my post in this thread on 3/4/20 with details. We've had numerous days of rain since then with no leaks so far.

As mentioned above if this continues to be a problem I'm going the solid window swap route, and will pay the cost out of pocket.

For me I love the truck. The hassle of dealing with this, while not ideal and really pathetic, is worth it as overall I'm really happy with the truck. I wouldn't own another Ford due to the numerous issues I had with my 2018 F150. I feel like my GMC is superior in just about every way.

As mentioned elsewhere in this thread it seems Ford and RAM trucks also have leaking sliders on some models. IMO the real issue is the crappy plastic window frames are mostly to blame.

This is just my 2cents, and I hope this helps you.

Edited March 22, 2021 by DSW1519

Fubar12 · March 22, 2021

Honsetly no matter what brand or car you buy there will always be an issue with something

I Own one and have not had an issue with any leaks

GN2018 · March 22, 2021

4 hours ago, DSW1519 said:

GN2018 - I truly understand your concerns and was in your position last fall.

I ordered a 21 and took delivery in December 2020. I ordered the truck being aware of the leaking slider issue, and because I liked the truck so much (and despised my 18 F150 so much) that it was worth the gamble. I also decided that if the slider became a continued issue I would pay the cost of swapping for a non-sliding window - and knew that was a possibility from the start.

Ten days into ownership the rear slider started leaking. Dealer performed the TSB and sealed the slider top gap. It was good until mid February, where I notice a slight drip after days of rain. It was a small enough leak that the towel I have on the rear seat back wasn't wet to the touch. Once we had a warm day I put a layer of flowable silicone on the top of the window gap - see my post in this thread on 3/4/20 with details. We've had numerous days of rain since then with no leaks so far.

As mentioned above if this continues to be a problem I'm going the solid window swap route, and will pay the cost out of pocket.

For me I love the truck. The hassle of dealing with this, while not ideal and really pathetic, is worth it as overall I'm really happy with the truck. I wouldn't own another Ford due to the numerous issues I had with my 2018 F150. I feel like my GMC is superior in just about every way.

As mentioned elsewhere in this thread it seems Ford and RAM trucks also have leaking sliders on some models. IMO the real issue is the crappy plastic window frames are mostly to blame.

This is just my 2cents, and I hope this helps you.

Maybe I can get the dealer to agree that if the leak happens, he'll put in the non-sliding window. In my 2018, I don't think I've ever opened the rear window except to play with it a couple times (see if it works . . .). If the non-slider is a genuine fix, I'd be okay with that.

Silverado4x4 · March 22, 2021

8 hours ago, GN2018 said:

I have a GMC Denali tagged. As of this moment, I have no obligation to buy it, but I’m that close. I’d be trading in my 2018 Silverado. My Silverado is an LT, so my main reason for buying is an upgrade in comfort and ride handling. However, the more I read about the rear window leak, the more I think I should just keep my 2018. If had no problems at all with my 2018. I feel like the rear window leak is so pervasive that I’d be trading a good truck for a bad one. I can imagine after a few years seeing these trucks with rust around the back window. It also seems like a problem that will always be there - can anyone say extended warranty?

Am I over reacting? Having got this far, I’m sure you can imagine that I really want this truck. Difference over trade it is $20K+. Spending that on a truck with a problem seems foolish.

The leakers are the slider windows only but not all of them, I have a full back glass no slider as I have had them before in the past and never used them and don't see the reason for them. Just get one without the slider and your good to go and not have to worry about it.

Transient · March 23, 2021

No leaking window so far. I'm so picky about my truck that I pay close attending to everything. I frequently look for a leak. I have a 2020 Trail Boss built in June 2020. I use the rear window as much as possible. I love opening the rear window and sunroof to let air flow through the cabin while driving, but have to deal with the affects of the for windows down. Imo, if you like it you should get it. Be attentive, and know there are lots of people who've had a leaky window, got it fixed, and haven't had further issues.

Sent from my SM-N960U using Tapatalk

TNTSierra · March 23, 2021

6 hours ago, Transient said:

No leaking window so far. I'm so picky about my truck that I pay close attending to everything. I frequently look for a leak. I have a 2020 Trail Boss built in June 2020. I use the rear window as much as possible. I love opening the rear window and sunroof to let air flow through the cabin while driving, but have to deal with the affects of the for windows down. Imo, if you like it you should get it. Be attentive, and know there are lots of people who've had a leaky window, got it fixed, and haven't had further issues.

Sent from my SM-N960U using Tapatalk

I agree. Love the combo in the morning letting cool air in.
I have a 2019 High Country and it leaked right away and I had dealer fix it and it hasn’t leaked since

I truly believe it comes down to oh well it’s fixed by the DEALERSHIP! There are good ones that will do it right and others that will just half @$$ it or have some oil changing rookie do it who has no clue what he/she is doing and tries following instructions from TSB.
I would also agree with others and wait. See what the 2022 looks and drives like.

hihosilverado · March 23, 2021

Based upon what I have seen in the other thread about this, the 2021 trucks do have a redesigned window but might be leakers right from the start due to missing sealant. I don't think anyone with a 2021 has found cracks in their window frames so if they are sealed right from the factory the issue might be a lot less likely to occur. My advice would be to get a truck if its a good deal but don't take delivery until it has sat in the rain a few days and you can inspect it. FWIW, I had a 2020 and now have a 2021 and neither have leaked.

OnTheReel · March 23, 2021

I just don’t trust ‘em yet. Not enough out there long enough to know. And whether it’s a sealant issue or a cracked frame or both, the end result is the same. Your brand new $60,000 truck gets wet and a dealer has to take it apart and probably damage things beyond what the water does. Might feel good in the short term to buy the new truck but nothing kills the buzz quicker than this issue.

I’m itching to trade for the refresh to get out of my leaker ASAP. But I will not until I see with some certainty that the issue is resolved. Imagine buying trucks 4 years apart that have the same issue.

GN2018 · March 23, 2021

Got a text from the salesperson tonight that the truck will be in tomorrow. I should be able to see it tomorrow or Thursday depending on when it comes in. I'm reluctantly inclined to go ahead with the deal. I'll see what the dealership says about the issue and go from there. Thinking about two things. First, have them test the window for leaks. This is actually good timing as it is supposed to rain pretty heavy Thursday night into Friday. They'll probably test it in a car wash, but some real world rain is a bonus. Second, have them take the spoiler off and just do the service bulletin. I'm guessing they won't do this, but I'll see how they react. Third, if it does leak and I'm not satisfied within a couple visits to the dealer, have them install a non-slider window.

Can ya'll sense that I really want the truck? This window issue sucks but I guess at least I get to go into it with eye's open. More than some were able to do.

Oh, the other thing I was thinking about is leasing the truck. Then, it may be an issue I have to deal with but not for long and I've locked in my exposure. We'll see.