Body problems of the 2020 GMC Sierra 3500

Four problems related to body have been reported for the 2020 GMC Sierra 3500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2020 GMC Sierra 3500 based on all problems reported for the 2020 Sierra 3500.

1 Body problem

Failure Date: 10/01/2025

Known defect with 2019 and now 2020 GMC sierra trucks. Design was updated for 2021+ which has corrected the seal failure defect. Gm has issued a service bulletin to dealers about how to repair the problem. Back window is leaking water. Defective seal noted by gm. Gm is only covering the cost of repair if. Vehicle is still under 3/36 warranty. If outside your warranty cost from dealer to owner is $2500 to $6000. A known design failure gm recognized and took steps to change the design for future. Vehicles but will not stand behind vehicles that have this defect. Would like the cost to the repair fall back to gm to cover. Bulletin # 18na383 [xxx] information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

2 Body problem

Failure Date: 03/07/2024

There is a current safety recall n232426400 on GMC pickups including the year of my truck. GMC is saying that my VIN is not covered by the recall. However, I have the multi-pro tailgate and it came open about 6 months ago on its own as I was backing up and it caused me to run into my trailer with the tailgate. I put my tailgate up after moving my truck from under my trailer and then when I went to back up somehow the tailgate popped open and I didnt know and it contacted the top of tailgate while it was down.

3 Body problem

Failure Date: 12/14/2022

Rear window leaking on 2020 GMC truck due to faulty rear window seal and plastic slide. Known issue in 2020 models with a service bulletin already in place. Headliner saturated and black mold showing. Rear back liner has been saturated multiple times and GMC would not refund the cost of a whole new window to be put in and reimbursed. Gm bulletin # is 18-na-383.

4 Body problem

Failure Date: 11/13/2022

Plugged in engine block heater and the car erupted in flames. Total loss.


Other Structure related problems of the 2020 GMC Sierra 3500

Body problems
4
Structure problems
1


Sierra 3500 Service Bulletins
Sierra 3500 Safety Recalls
Sierra 3500 Defect Investigations