The contact owns a 2021 Chevrolet Silverado 2500. The contact stated while driving 55-60 MPH, the rear wheels seized. The contact had to release the accelerator pedal to self-correct the failure. The contact stated that the failure occurred twice. The vehicle was taken to the dealer, and the contact was informed that the vehicle was included in NHTSA Campaign Number: 24V797000 (Power Train); but…
2021 Chevrolet Silverado HD powertrain problems
moderate 26 complaints filed with NHTSA · avg repair $2,500 · see powertrain across all vehicles →
Complaints
26
Recalls
0
Avg fix
$2,500
1injury
When does it fail?
Of the 26 powertrain complaints filed for the 2021 Chevrolet Silverado HD, here's the actual mileage breakdown — failures cluster heaviest at 100,000-125,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Powertrain accounts for 32% of every owner complaint on file for this vehicle — the dominant problem area across 3 categories tracked.
Owners have filed 26 powertrain complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
The failure pattern owners describe
Owners of this 2021 Silverado 2500 HD are reporting critical powertrain failures. The most serious involve transmission control defects causing sudden rear wheel lockup and violent downshifts at highway speed while towing—incidents that have caused trailers to fishtail and vehicle control to be nearly lost. Multiple owners describe the transmission entering fail-safe mode, locking in a single gear with abnormally high RPM, or losing all power mid-intersection in traffic. In some cases the transmission fluid is burnt and contaminated with metal debris. GM has issued a recall (N242454440 and N242454441) pairing software updates with special coverage for defective valve bodies, but owners report dealers refusing to honor the coverage or delaying repairs indefinitely due to parts shortages. One owner documented the dealership refusing recall coverage after the emission system was modified. Beyond transmission issues, owners report transfer case moisture and corrosion recurring multiple times despite repairs, a cluster of carbon monoxide poisoning incidents following DPF replacement, and transmission cooler line separation at the crimp joint causing complete fluid loss. Some owners face intermittent-to-constant 'Shift to Park' sensor failures that prevent vehicle locking and shutdown, related to a known steering column defect. The powertrain failures span mileages from 25,000 to 130,000 miles, with one owner's truck requiring complete engine replacement and another stranded in traffic multiple times.
Same Chevrolet Silverado HD powertrain reports on nearby years: 2020 · 2022 · 2023 · 2024
Failure modes owners describe
Transmission pressure control and valve body defects
Transmission experiences harsh downshifts, momentary rear wheel lockup, and loss of power. Defective control valve body causes transmission to enter fail-safe (limp mode) or lose normal shifting. Some owners report violent downshifts when under load (towing), wheel lockup while driving, and inability to shift properly. Transmission fluid found burnt and contaminated with metal debris in some cases.
When: Occurs at highway speeds (40-60+ mph), under acceleration, while towing, and at various mileages from 77,800 to 122,000 miles. One case at 25,000 miles.
Symptoms owners cite: Sudden hard jolt followed by rear wheel lockup; Transmission locked in single gear (4th gear reported); Abnormally high RPM and engine load at highway speeds; Violent downshifts from 8th to 7th or 6th gear causing wheel lockup; Loss of control while towing (fishtailing, near jack-knifing); Vehicle enters limp mode, cannot exceed 35-40 mph; Shuddering before downshift while towing under grade; Transmission fluid burnt and contaminated with metal debris; Loss of power in heavy traffic
Codes mentioned: P2715, P2733, P0747
Repairs/costs cited: Transmission valve body replacement; some dealers replacing entire transmission with remanufactured unit (approx. $7,000); transmission cooler inlet/outlet pipe replacement in some cases. Internal transmission damage not addressed by dealerships in some cases despite valve body replacement.
Recalls/TSBs owners mention: GM Special Coverage N242454441 for valve body defect causing harsh shifting and reduced power; NHTSA Campaign N242454440 (momentary rear wheel lock-up) includes transmission and engine control module software update; Campaign 24V797000 (Power Train). Software updates reported to limit drivability and power output. Dealers refusing to honor special coverage in some cases; dealerships delaying repairs or unable to complete recalls due to parts not being available.
Engine knock, fuel burning, and internal damage
Engine develops knock and burns fuel excessively. Initial fuel injector replacement fails to resolve problem. Subsequent diagnostics reveal rocker arm wear, cylinder damage, valve failure, and piston damage. Vehicle requires complete engine replacement at 130,000 miles despite full maintenance records and prior injector replacement.
When: First failure April-May 2025 at unknown mileage; recurring issue December 2025; total time in shop approximately 2 months over one year.
Symptoms owners cite: Engine knocking; Excessive fuel burning; Reduced speeds on highway; Check engine warning light; Vehicle fails engine regeneration test
Repairs/costs cited: Two fuel injectors replaced initially; remaining six fuel injectors replaced afterward (total eight fuel injectors); rocker arms replaced; cylinder and valve replaced; entire engine replacement needed but not yet completed at time of complaint.
Carbon monoxide intrusion after DPF replacement
After DPF filter replacement in August 2022, owner experiences carbon monoxide poisoning symptoms while driving. Multiple trips to dealership result in no diagnosis or correction despite symptoms recurring over three months. Owner hospitalized twice with severe symptoms (loss of consciousness, worst headache, nausea, seizures, chest pain). Vehicle remains at dealership for 70 days without update.
When: Began July 2022 with check engine light; DPF replaced August 19, 2022; symptoms continued through October, November; truck at dealership 70 days at time of complaint.
Symptoms owners cite: Carbon monoxide poisoning symptoms (confirmed hospital diagnosis); Severe headaches; Loss of consciousness; Nausea for extended periods; Loss of feeling in body; Seizing of body; Chest pain
Repairs/costs cited: DPF filter replaced August 19, 2022; dealership unable or unwilling to diagnose or repair the carbon monoxide intrusion issue despite three inspections.
Transfer case moisture intrusion and sensor corrosion
Transfer case develops moisture intrusion leading to sensor corrosion, triggering 'Service 4WD' light and grinding noise in front axle. Issue recurs multiple times after repairs. First repair involved diagnosis and correction; second repair required wiring harness replacement; third occurrence at 34,458 miles.
When: First occurrence at 25,000 miles; second occurrence less than 3,000 miles after first repair (approx. 28,000 miles); third occurrence at 34,458 miles.
Symptoms owners cite: Service 4WD warning light on dash; Grinding noise/sound in front axle transfer case
Repairs/costs cited: First repair completed after one week in shop; second repair included wiring harness replacement and more extensive work; third occurrence still under diagnosis at time of complaint.
Transmission fail-safe mode and clutch pack failure
Vehicle experiences two distinct clutch/transmission control failures: (1) clutch pack welds together from friction, causing vehicle to roll backward when brakes released and RPM to spike to 5,000 when brake applied; (2) vehicle loses response to accelerator pedal while depressing accelerator at 45 mph, requiring towing. Second case resulted in recall campaign referral but dealer refused to honor recall due to emission system removal.
When: First case at approximately 100,000 miles; second case at approximately 27,000 miles.
Symptoms owners cite: Vehicle rolls backward when accelerator depressed in drive with brakes applied; RPM elevated to 5,000 RPM when brake applied; Clutch pack friction welds together; Complete loss of vehicle response to accelerator pedal at highway speed (45 mph); No warning lights illuminated (both cases)
Repairs/costs cited: First case: dealer identified clutch pack welding but did not diagnose or repair; second case: vehicle towed to Patterson Custom Diesel for repair after John Elway Chevrolet refused recall repair.
Recalls/TSBs owners mention: NHTSA Campaign 24V797000 (Power Train) applicable to second case, but dealer refused to honor recall citing emission system removal; manufacturer exceeded reasonable time for repair (vehicle towed to multiple dealers over months).
Shift to Park sensor failure
Transmission shift lever does not register when moved to park position, causing 'Please Shift to Park' message and inability to lock vehicle doors. Failure becomes regular occurrence; issue escalates from intermittent to constant over vehicle life. Related to broader steering column defect affecting 2019-2025 GMC and Chevrolet models.
When: One case at 25,000 miles with recurring occurrences; another case at 72,000 miles where intermittent failures became constant.
Symptoms owners cite: Vehicle fails to recognize shift lever moved to park; 'Please Shift to Park' warning message displayed; Doors unable to be locked; Failure becomes regular/constant occurrence; Vehicle remains in auxiliary power mode and will not fully shut off
Repairs/costs cited: No repairs completed in reported cases; one vehicle not taken to dealer or mechanic.
Recalls/TSBs owners mention: Manufacturer referred one owner to NHTSA Hotline for assistance. Known widespread defect in steering column parts that prevent proper park engagement and vehicle shutdown.
Transmission cooler line separation
Transmission fluid cooler line connection fails at the crimp joint where rubber and metal tube connect. Rubber and metal separation results in complete loss of transmission fluid while driving, causing vehicle to lose power and strand driver.
When: One case at 40 mph while driving on road; timing/mileage for both cases not specified.
Symptoms owners cite: Transmission fluid sprays from cooler line connection; Transmission fluid loss while driving; Complete loss of vehicle power; Vehicle becomes stranded
Repairs/costs cited: Two separate complaints; exact repair not detailed, but transmission cooler inlet/outlet pipe replacement noted in one powertrain cooler failure complaint.
Transmission shifting and power loss
While in motion, transmission exhibits multiple abnormal behaviors: erratic shifting with noticeable kick/shudder, unexpected downshifts without driver input, and sudden complete loss of power as if transmission shifted to neutral. No diagnostic codes or warning lights reported.
When: No specific mileage or timing provided.
Symptoms owners cite: Noticeable kick when transmission shifts gears; Unexpected downshifts without driver input; Complete loss of power during motion (transmission acts as neutral); No warning lights or check engine codes illuminated
DEF tank heater failure and limp mode
DEF (diesel exhaust fluid) tank heater fails after defined mileage, forcing vehicle into limp mode. Dealer confirms part failure but replacement part on backorder with no known production date.
When: After defined mileage threshold (exact mileage not specified).
Symptoms owners cite: Vehicle enters limp mode; Reduced power and drivability
Repairs/costs cited: DEF tank heater identified as failed; replacement part on backorder with unknown production date.
Synthesized from 26 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 3 most recent
While the truck is in motion and the transmission shifts gears it has a kick to it also it down shifts on its own and other times the truck loses all power like if it was in neutral
The contact owns a 2021 Chevrolet Silverado 2500. The contact stated that while slowing down and coming to a stop, the accelerator pedal was depressed while in drive; however, the vehicle started to roll backwards. The contact depressed the brake pedal to prevent the vehicle from rolling backwards, and the RPM became elevated to 5,000 RPM. The contact immediately turned off the vehicle to prevent…
Had powertrain trouble with your 2021 Chevrolet Silverado HD?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the powertrain problem on the 2021 Chevrolet Silverado HD?
It's a documented issue but not catastrophic. 26 complaints have been filed. Repairs average $2,500 and most owners catch it before it causes a breakdown.
At what mileage does the powertrain typically fail?
Based on the 26 complaints filed, powertrain issues most often appear around 73,600 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to powertrain?
No active recalls currently cover powertrain issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2021/Chevrolet/Silverado HD.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.