Rear Window Leak on 2020 3500HD Denali

Pate Services · July 23, 2020

Well I have had my truck for just over one week and just noticed a small wet spot on the top of the rear window on the drivers side. It's where the top plastic slider frame ends. If I look closely I can see a few verticle streaks in the glass from where it must have leaked previously. Under 300 miles and its going back to the dealer tomorrow.

sdelam · July 23, 2020

I have a leaky window also, both sides of rear glass. Dealership says there are parts (self sealing nut?) that are back ordered and they wont pull the spoiler to do the fix until they get them.

gearheadesw · July 23, 2020

So, bummer, sorry to hear this. Both the new 1500 and now the 2500's have leaks, truly WTF, why can't GM build a water tight vehicle?

greatmizzou · July 24, 2020

My chevy 3500 LT is not having this issue

are there different designs??

Pate Services · July 25, 2020

Got the truck back from dealer. There is a bulletin for the repair. Essentially they pull down the back part of the headliner and remove the rear spoiler. They then apply seam sealer to the top of the window seal where the water is getting in. I believe the issue is the plastic frame that the sliding window is in may have hairline cracks allowing water in between that and the window seal. Seems like a crappy fix but let's see if it holds. Worst part is they got some of the sealer on the spoiler. I asked them to clean it and they scuffed up the clearcoat in the process. They then had to buff it out. They also broke a clip in the headliner. I hate that a truck with 300 miles has to be torn apart for bullshit quality from GM.

greatmizzou · July 25, 2020

Did the dealer fix it? Honestly they should do that stuff at their bodyshop and not the standard mechanic bay

Pate Services · July 26, 2020

11 hours ago, greatmizzou said:

Did the dealer fix it? Honestly they should do that stuff at their bodyshop and not the standard mechanic bay

Everything fixed and broken clip is ordered. I will know shortly after I wash it if the leak is resolved.

Pate Services · August 4, 2020

Didn't notice any leaks in the past few rains but it poured today and it leaked in the same spot. Dealer is now ordering a new rear window.

ShotgunZ71 · August 5, 2020

MIne goes back tomorrow for another repair attempt per the GM Case Mgr. If this also fails, apparently the next step is a new rear window.

Sure hope the new, upgraded ones are leak free for the life of the truck.

kylant · August 9, 2020

i hope they have fixed this issue from the factory.

I have a truck coming. currently on the train. scheduled delivery is the 13th

ShotgunZ71 · August 9, 2020

On 8/5/2020 at 3:36 PM, ShotgunZ71 said:

MIne goes back tomorrow for another repair attempt per the GM Case Mgr. If this also fails, apparently the next step is a new rear window.

Sure hope the new, upgraded ones are leak free for the life of the truck.

The next step is to replace the spoiler bolts with the upgraded bolts and washers. So, new spoiler, sealer, and now bolts and washers. GM knows that the new window is the true fix, but they want to hassle dealers to try things a piece at the time so see if other remedies work. I hate that the service departments and customers have to deal with the drawn-out process, simply because GM keeps trying to cheap out and the dealers don't get paid unless they follow those steps.

Edited August 9, 2020 by ShotgunZ71

Stand By · August 14, 2020

There are two issues. Make sure they take care of both. One is the window frame cracking. The other is the bolts for mounting the spoiler not sealing right.

doozer78 · August 17, 2020

These leaks I keep hearing about is there a timeline for build dates that are affected by this? Are the more recent builds already Fixed? Just wondering so I know to keep an eye on things.

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Camper Hauler · August 19, 2020

On 8/13/2020 at 7:50 PM, Stand By said:

There are two issues. Make sure they take care of both. One is the window frame cracking. The other is the bolts for mounting the spoiler not sealing right.

I've been trying to tell them the leak is ABOVE the window, is in the spoiler bolts. Water does not typically run up hill!