2021 Chevrolet Silverado 2500HD: Power Train complaints
Owner-reported issue (NHTSA complaints, not a recall)
Symptoms
NHTSA has 30 owner complaints for the 2021 Chevrolet Silverado 2500HD that list the power train component. Complaints are individual owner reports, not verified defects.
Examples:
- NHTSA complaint ODI #11769229 (filed 10/06/2026): “Vehicle braking does not work- since new- dealer said it was funcitioning- sometimes you will get the warning and other times it does not and it never brakes. transmission- i received a letter to bring truck in to have a software update for modulator valve wear....which was performed...since that ti…”
- NHTSA complaint ODI #11766354 (filed 09/23/2026): “Pulling out from a stop sign, a loud bang came from the transmission, and rear wheels momentarily locked up then truck acted like it was in neutral. truck was able to drift to side of road. we called our gm dealer, and they told us that our warranty had expired. we had the truck towed to our certifi…”
- NHTSA complaint ODI #11752243 (filed 07/22/2026): “My 10l1000 transmission had a catastrophic failure internally which caused it to rough shift, sudden down shifting, not want to shift into gear at all, and high engine rpm prior to roughly shifting. i took it to the chevy dealers mechanic the very next business day, only to find out that from the me…”
Likely causes
These complaints do not establish a single root cause; read the examples above and get a diagnosis.
Fix, in plain English
No single fix is established by these reports. Check your VIN for open recalls at nhtsa.gov/recalls, ask a dealer about technical service bulletins (TSBs) or extended warranty coverage, then have the system diagnosed.
DIY difficulty: Pro
Diagnosis needs a scan tool; repair or replacement needs a lift, transmission jack and the manufacturer's fluid fill/relearn procedure. (Our assessment.)
Cost
No sourced cost range for this issue. Get a written quote after diagnosis.
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