Rear Window Leak on 2020 3500HD Denali

Pate Services · September 22, 2020

Dealership says the new replacement window is cracked and leaking same as orginal one. They are ordering a second new window. Total bs quality.

ShotgunZ71 · September 23, 2020

Mine still leaks after 3 tries. The TSB, new spoiler and new spoiler bolts. Not real sure what to try next. Thought of calling another dealer to see if they've had any success or possibly just trying to seal it myself. Some weatherstripping and silicone caulk may do some good. The frames may get cracks we can't even see that leak. Disappointing for anyone to have this and GM has no reliable repair.

ShotgunZ71 · September 23, 2020

5 hours ago, Pate Services said:

Dealership says the new replacement window is cracked and leaking same as orginal one. They are ordering a second new window. Total bs quality.

That's a shame. I wonder how many leak and the owners don't even know?

shadow gray 2020 hd · September 23, 2020

No doubt that would be a turn off. Hope they get it straight for you. Situations like this, would seem gm would be eager to give their customers some compensation for the time involved. Unfortunately it seems most auto makers have their issues they fail to address in a fair time frame.

Dodge screwed us over on our awd limited durango with a hemi. Bought it new in 08 with a lifetime powertrain warranty. Was a recall for the gas filler spout for it pouring gas out when filling about 6 years in. Made complaints to the servicing dealer several times, and finally they fixed it with the recall. Last year it developed rust through directly under the filler door. The only rust anywhere on the vehicle, has been for the most part garage kept and driven in TN where exposure to salted roads is not an issue. Dodge knows this is an issue that they are to blame for, but they refuse to fix it. I have seen loads of the same body style with the same rust through from minor to so bad there are large holes. For that sole reason I took dodge off the table for consideration on our new truck.

greatmizzou · September 27, 2020

So I powerwashed my truck a few days ago and specifically nailed the top spoiler and rear sliding glass window to see if it would leak.

No leaks

Sorry man good luck!

Pate Services · September 29, 2020

So today was the day my truck went in to get the second replacement window installed. They informed me they found a gap in the top bead of sealant that was from the last install. Rather than replace the window as planned to correct the flaw they dropped the headliner and pulled the spoiler. They put a thick bead of sealant along the top just like they did in the first repair attempt. Best part is they ran it though their car wash to leak test it and they crushed my passenger side mirror. Truck now needs a whole new side mirror. Unreal.

Stand By · October 1, 2020

I remember years a go when extended cabs became popular, there were some after market vendors that made power window kits for the rear window. I don't think sliders were available for awhile, just like the 3rd door option in 97, finally. Curious what kind of market there would be right now for a power rear window install to alleviate the leak headaches?

Omega · January 30

Same issue here in Vancouver Washington. Service Advisor (SA) says he’s NEVER had a GM truck with this problem before. I live in a Rain Forest and I’m the first one he’s ever seen with this issue. WTH? Guess he was hired this morning. Does anyone have any TSBs related to leaking rear sliding window and/or top center mounted exterior brakelight? Thanks for everyone’s comments regarding roof and window leaks. I’m trying to get GM to help pay for this repair which has been reported in places like this for years. Yeah I know; good luck with that. Many thanks again from a 41-year Air Force Veteran.

Edited January 30 by Omega
Added request for appropriate TSBs for these issues