What are the common problems with the 2021 GMC Sierra 3500?
Owners of the 2021 GMC Sierra 3500 have filed 21 complaints with NHTSA, most often about the powertrain (7). In NHTSA's complaints file of November 11, 2026, 4 of its 21 complaints list a mileage (26,000 to 140,606 miles), too few to say when problems were reported; a complaint is an owner's report, not a proven defect.
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See what the paid report includes →NHTSA's file holds 21 owner complaints on the 2021 GMC Sierra 3500. Owners named the powertrain most often: 7 complaints. A complaint can name more than one component. None of the 21 complaints reports a crash, a fire or an injury.
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Common problems with the 2021 Sierra 3500
NHTSA's file holds 21 owner complaints on the 2021 GMC Sierra 3500. Owners named the powertrain most often: 7 complaints. A complaint can name more than one component.
| Component (NHTSA category) | Complaints | Listing mileage | Median mileage |
|---|---|---|---|
| Power Train | 7 | 1 | Under 5 mileages |
| Electrical System | 5 | 1 | Under 5 mileages |
| Service Brakes | 5 | 1 | Under 5 mileages |
| Engine | 3 | 0 | Under 5 mileages |
| Back Over Prevention | 2 | 1 | Under 5 mileages |
None of the 21 complaints reports a crash, a fire or an injury.
Mileage when owners reported a problem with the 2021 Sierra 3500
Too few complaints on the 2021 Sierra 3500 list a mileage to say when owners reported problems: 4 of its 21 complaints list a mileage (26,000 to 140,606 miles), and a median is given here only with 10 or more.
These mileages say when owners reported a problem, not when a 2021 Sierra 3500 wears out. NHTSA's file holds only vehicles whose owners complained; one that ran without a problem never appears in it, so it gives no lifespan and no cutoff, and how a vehicle was maintained matters more than any one odometer reading.
Is the 2021 Sierra 3500 a good year?
Complaint counts cannot say whether the 2021 is a good or a bad Sierra 3500: they rise with how many were sold and how long they have been on the road. They show how the 2021 compares with the other model years in NHTSA's file.
With 21 complaints, the 2021 ranks 11th of the 24 GMC Sierra 3500 model years from 1997 to 2025 with 10 or more complaints, counting from the most. The most: the 2024 (52). The fewest: the 1997 (10).
Recent model years have had less time to collect complaints, so their counts are still growing. No year is ranked by mileage here, because a year's median mileage mostly follows its age.
| Model year | Owner complaints | Listing mileage | Median mileage |
|---|---|---|---|
| 1997 Sierra 3500 | 10 | 1 | Under 10 mileages |
| 1998 Sierra 3500 | 12 | 4 | Under 10 mileages |
| 1999 Sierra 3500 | 19 | 8 | Under 10 mileages |
| 2000 Sierra 3500 | 26 | 15 | 57,007 |
| 2001 Sierra 3500 | 36 | 30 | 61,580 |
| 2002 Sierra 3500 | 20 | 14 | 78,000 |
| 2004 Sierra 3500 | 24 | 22 | 81,000 |
| 2005 Sierra 3500 | 24 | 22 | 46,000 |
| 2006 Sierra 3500 | 11 | 10 | 45,949 |
| 2007 Sierra 3500 | 16 | 9 | Under 10 mileages |
| 2008 Sierra 3500 | 25 | 10 | 50,000 |
| 2011 Sierra 3500 | 20 | 10 | 57,000 |
| 2013 Sierra 3500 | 14 | 8 | Under 10 mileages |
| 2015 Sierra 3500 | 31 | 22 | 37,000 |
| 2016 Sierra 3500 | 19 | 7 | Under 10 mileages |
| 2017 Sierra 3500 | 13 | 6 | Under 10 mileages |
| 2018 Sierra 3500 | 14 | 7 | Under 10 mileages |
| 2019 Sierra 3500 | 13 | 5 | Under 10 mileages |
| 2020 Sierra 3500 | 51 | 10 | 28,000 |
| 2021 (this page) | 21 | 4 | Under 10 mileages |
| 2022 Sierra 3500 | 33 | 10 | 31,000 |
| 2023 Sierra 3500 | 28 | 3 | Under 10 mileages |
| 2024 Sierra 3500 | 52 | 10 | 36,000 |
| 2025 Sierra 3500 | 18 | 1 | Under 10 mileages |
2021 GMC Sierra 3500 recalls
NHTSA's recall files of November 11, 2026 list 5 recall campaigns that name the 2021 GMC Sierra 3500. A campaign covers a production range, not every vehicle of the model year: check the VIN with NHTSA's free recall lookup.
| Campaign | Report received | Component |
|---|---|---|
| 24V797000 | Oct 24, 2024 | POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT:VALVES/VALVE BODY |
| 24V060000 | Feb 1, 2024 | LATCHES/LOCKS/LINKAGES:TAILGATE:LATCH |
| 21V758000 | Sep 29, 2021 | SERVICE BRAKES, HYDRAULIC:POWER ASSIST:ELECTRIC:CONTROL MODULE |
| 20V811000 | Dec 23, 2020 | SEAT BELTS:CRITICAL FASTENERS |
| 20V792000 | Dec 17, 2020 | SEAT BELTS:CRITICAL FASTENERS |
What these figures can and cannot tell you
- Complaints are owners’ reports to NHTSA. NHTSA publishes them without verifying them: a complaint is an allegation, not a defect finding.
- The mileage is what the owner wrote on the complaint; NHTSA does not check it against the odometer.
- The make, model and model year are the ones on the complaint. NHTSA records them as filed, so a few complaints sit under a model year the name was not sold in.
- They are not a lifespan study. The file holds only vehicles whose owners reported a problem, so these figures do not say how long a typical 2021 Sierra 3500 lasts.
- A complaint count rises with how many vehicles were sold and how long they have been on the road, so it is not a rating of the 2021 Sierra 3500.
- Nothing here describes one vehicle: its title brands, odometer readings, accidents and open recalls are in the records for its own VIN.
- 17 of the 21 complaints on the 2021 GMC Sierra 3500 give no usable mileage (blank, zero, a filler such as 999999, or over 500,000) and are left out of every mileage figure.
- NHTSA name counted: SIERRA 3500. NHTSA files some vehicles under several names (a series name and a trim name, for example); this page counts only this one.
- Recall-file name matched: SIERRA 3500.
Primary sources behind this page
Open the underlying public source and verify that its scope matches the question you are asking.
- NHTSA complaints flat file (FLAT_CMPL.zip), downloaded November 11, 2026National Highway Traffic Safety Administration
- Complaints file field layout (CMPL.txt)National Highway Traffic Safety Administration
- NHTSA recalls flat file (FLAT_RCL_PRE_2010.zip), downloaded November 11, 2026National Highway Traffic Safety Administration
- NHTSA recalls flat file (FLAT_RCL_POST_2010.zip), downloaded November 11, 2026National Highway Traffic Safety Administration
- Recalls file field layout (RCL.txt)National Highway Traffic Safety Administration
- NHTSA recall and complaint datasets: scope and documentationNational Highway Traffic Safety Administration
- Recalls Lookup by VINNational Highway Traffic Safety Administration
NHTSA’s complaints file was downloaded on November 11, 2026 (FLAT_CMPL.txt, dated 2026-11-11 10:15, 2,265,416 rows), with its recall files (FLAT_RCL_PRE_2010.txt and FLAT_RCL_POST_2010.txt, dated 2026-11-11 08:02). Each complaint is counted once, by its NHTSA number, with the model year and mileage of its first row; a model year has a page only with 10 or more complaints. The collection script and its rules are in scripts/collect-nhtsa-model-year-longtail.mjs.
2021 GMC Sierra 3500 questions
What are the most common 2021 GMC Sierra 3500 problems?
NHTSA's file holds 21 owner complaints on the 2021 GMC Sierra 3500. Owners named the powertrain most often: 7 complaints. A complaint can name more than one component. None of the 21 complaints reports a crash, a fire or an injury.
At what mileage do owners report problems with the 2021 GMC Sierra 3500?
NHTSA's file gives no mileage figure for the 2021 GMC Sierra 3500: 4 of its 21 complaints list a mileage (26,000 to 140,606 miles), and this page gives a median only with 10 or more. These are mileages at a reported problem; they do not say how many miles a 2021 Sierra 3500 can cover.
Is the 2021 GMC Sierra 3500 a good year?
Complaint counts cannot say whether the 2021 is a good or a bad Sierra 3500: they rise with how many were sold and how long they have been on the road. They show how the 2021 compares with the other model years in NHTSA's file. With 21 complaints, the 2021 ranks 11th of the 24 GMC Sierra 3500 model years from 1997 to 2025 with 10 or more complaints, counting from the most. The most: the 2024 (52). The fewest: the 1997 (10).
How many recalls does the 2021 GMC Sierra 3500 have?
NHTSA's recall files of November 11, 2026 list 5 recall campaigns that name the 2021 GMC Sierra 3500. A campaign covers a production range, not every vehicle of the model year: check the VIN with NHTSA's free recall lookup.
How do I check a used 2021 GMC Sierra 3500 before buying?
Take the 17-character VIN from the vehicle and compare the odometer with the readings on file for it: title transfers, inspections and auction sales record the mileage on the day. VIN Lookup (free-vin-lookup.com) sells the original ClearVIN PDF for $14.99 (3 reports for $29.99, 5 for $44.99): odometer readings, title brands and auction records on file for the VIN. Check the VIN before buying a used 2021 GMC Sierra 3500.