Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure within the valve. The effects can cause harsh shifting, setting a service engine soon message, reduced engine performance or P0747 diagnostic trouble code. Dealers are to install a new control valve body. The repairs will be made at no charge to the customer.
full bulletin at NHTSA ↗2021 Chevrolet Suburban powertrain problems
moderate 31 complaints filed with NHTSA · avg repair $2,500 · see powertrain across all vehicles →
Complaints
31
Recalls
0
Avg fix
$2,500
What stands out
Of the 8 model years of Chevrolet Suburban we track for powertrain problems, this one carries the most owner complaints on file — 31.
Owners have filed 31 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.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering powertrain on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
Certain vehicles listed above, may have a condition where the connecting rod and/or crankshaft engine components in these vehicles may have manufacturing defects that can lead to engine damage and engine failure. This special coverage covers if an engine failure occurs in the vehicle as a result of the condition described above for a period of 10 years or 150,000 miles (240,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after May 23, 2025, are covered by this special coverage and must be submitted using the labor operation code
full bulletin at NHTSA ↗This service bulletin advises the technician to check if the transmission cooler lines are twisted to correct customer concerns of Harsh Shift, Shudder, Surge, Stall, Transmission Overheating and/or High Transmission Fluid Temperature.
full bulletin at NHTSA ↗This preliminary informational (PI) bulletin provides information to dealership personnel that may be helpful when addressing underbody component corrosion with customers.
full bulletin at NHTSA ↗This service bulletin helps diagnose/reduce possible CCND issues on Transfer Cases - Service 4WD on DIC, Intermittent Failures, Noise Concerns, Driveline/Steering Vibration/Shudder, Intermittent DTCs/MIL Illuminated, Engagement/Disengagement/Ratcheting Concerns.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The 2021 Chevrolet Suburban's powertrain shows a pattern of critical failures across multiple systems. Engine lifter problems dominate: owners report lifter failure as early as 8,000 miles, often repeating on the opposite side after dealership repair. One owner had lifters replaced at 60,000 miles under warranty, then the driver-side lifters failed again at 80,200 miles, out of warranty, with repair costs around $10,000.
Transmission failures are severe and widespread. Owners describe metal shavings in fluid, broken gears and valve bodies, sudden inability to shift into reverse or upshift, and limp-mode activation. One customer faced a $9,200 repair bill for a remanufactured transmission at 93,000 miles. The transmission control valve body is a recurring culprit, causing reduced acceleration and stuck-in-gear conditions.
Loss of propulsion without warning is the safety red flag. Multiple owners report sudden, complete engine shutdown at highway speeds—one at 60 mph in traffic, unable to steer or brake the vehicle to safety. Diesel models report recurring ECM warning lights every 8,000 miles from 20,000 onward, with GM seemingly delaying diagnosis until warranty expires. Uncontrolled acceleration, hard shifting, and electrical cascades (multiple warning lights firing in rapid succession) round out the complaints. Dealerships acknowledge these as known issues but recall coverage remains inconsistent—some VINs are excluded despite experiencing the exact failures described in existing NHTSA recalls.
Same Chevrolet Suburban powertrain reports on nearby years: 2022
Failure modes owners describe
Complete engine shutdown and total loss of motive power
Engine loses all power without warning, vehicle cannot be driven, often accompanied by automatic neutral engagement or shift into park without driver input. In some cases the vehicle becomes completely immobilized and cannot shift out of neutral. Customers report dashboard warnings like 'press the start button again' and 'engine recall' preceding failure.
When: Reported between 7,000 and 84,000 miles; two cases specifically during highway operation at 60 mph and on local roads
Symptoms owners cite: sudden loss of engine power; vehicle shifts to neutral or park automatically; vehicle will not re-engage drive or shift out of neutral; inability to accelerate; complete immobility; engine will not start or restart; dashboard warnings for 'press start button' and 'engine recall'; loss of propulsion mid-drive
Repairs/costs cited: One case involved fuel pump modulator replacement and belt pulley system work. One dealership quoted ~$10,000 for lifter and camshaft repair. Another customer was told the lifter failure is not covered under the recall because it involves the top of the engine.
Recalls/TSBs owners mention: Recall mentioned for L87 6.2L V8 engines; however, owners report active recalls not fully addressing the problem and some repairs being excluded from coverage despite recall existence. Service bulletins referenced for lifter issues.
Lifter failure
Engine lifters fail prematurely, causing engine chugging, rough running, and eventually complete loss of propulsion. Typically diagnosed via check engine light and confirmed at dealership. Owners report that initial replacement of lifters on one side has led to failure on the other side. One owner reported lifters failed at just 8,000 miles.
When: First occurrence around 60,000-80,000 miles; repeat occurrences shortly after initial repair (one year later in one case). One case reported failure at 8,000 miles.
Symptoms owners cite: engine chugging; vehicle lunging forward; check engine light; loss of propulsion
Repairs/costs cited: Lifter replacement performed at dealership under warranty initially. Owners report the dealer refused to replace lifters on both sides despite known pattern, leading to failure on opposite side out of warranty. One case mentioned $10,000 cost for lifter and camshaft repair.
Recalls/TSBs owners mention: Service bulletin recognized for lifter replacement on L87 6.2L engines. Owners indicate this is a known defect with a class action lawsuit filed against GM.
Transmission failure with metal debris and internal damage
Transmission loses the ability to shift or engage gears properly. Customers report metal shavings in transmission fluid, broken gears, and broken valve body. Vehicle may shift into limp mode, lose ability to shift into reverse or higher gears, or become stuck unable to shift at all. One case involved complete transmission failure at 93,000 miles.
When: Reported between 75,000 and 119,800 miles; one case at 93,000 miles with metal debris in fluid indicating internal failure
Symptoms owners cite: inability to shift into reverse; vehicle stuck in low gear with 3,500 rpm limit; transmission in limp mode; hard or jerking shifts; unable to upshift; transmission sticks in gear; metal in transmission fluid; broken gears and valve body; leaking transmission fluid
Repairs/costs cited: GM remanufactured transmission quoted at ~$9,200. One customer reported the dealership charged $504 for transmission flush. Another case involved transmission control valve replacement.
Recalls/TSBs owners mention: Customers indicate there is an active class action lawsuit against GM for defective transmissions. NHTSA recall 24V797000 mentioned but not covering all affected VINs. Some customers were told their VIN was not included in any recall despite experiencing the exact described failure.
Transmission control valve body failure
Transmission control valve body malfunctions, causing reduced acceleration, inability to upshift, limp mode activation, and loss of motive power. Dealers have identified this as a known issue requiring valve body replacement.
When: Reported at 75,000-81,600 miles
Symptoms owners cite: vehicle speed suddenly reduced; transmission stuck in low gear or limp mode; unable to shift into next gear; warning light 'Reduced Acceleration Drive with Care'; transmission stuck in gear
Repairs/costs cited: Dealership service identified transmission control valve body as needing replacement. One case was not repaired; current diagnosis pending in another.
Recalls/TSBs owners mention: Dealers acknowledge this is a known issue. NHTSA recall mentioned but not all VINs covered.
Hard or jerking transmission shifts
Transmission shifts roughly or jerks unexpectedly during gear changes, particularly at low speeds or from a stop. Issue persists despite multiple dealership service attempts. Some cases involve vehicle lunging forward or abnormal jerking during shift transitions.
When: Reported as ongoing issue; one case persisting for extended period despite multiple dealer visits
Symptoms owners cite: hard or jerking shifts; vehicle jerks when shifting into reverse or drive; vehicle lurches forward; abnormal feel when depressing accelerator; loud or funny sounding transmission
Repairs/costs cited: Dealerships have attempted multiple repairs but could not resolve the issue in some cases. One dealership stated the noise was normal for the vehicle.
Fuel control module failure
Fuel control module fails, causing sudden loss of engine power while driving. Vehicle dies mid-operation and will not restart. Owner reports having the fuel control module replaced previously under a recall that did not cover their VIN, and then experienced the same failure again.
When: Replacement performed in 2022; second failure occurred in 2024 or later (date not specified)
Symptoms owners cite: vehicle suddenly dies while driving; vehicle will not restart; loss of power while in gear
Repairs/costs cited: Fuel control module replacement performed at dealership in 2022. Second failure pending diagnosis at dealership.
Recalls/TSBs owners mention: NHTSA recall N212332040 exists but the owner's VIN was excluded despite experiencing the exact recalled failure. Owner specifically requests NHTSA expand the recall to include other VINs.
Engine oil and cooling system issues
Engine oil-related problems noted in recalls contributing to lifter and camshaft failures. Owners report crankshaft synchronization issues with lifters, indicating oil supply or pressure problems.
When: Contributing to failures between 7,000 and 84,000 miles
Symptoms owners cite: lifter failure; camshaft issues; crankshaft synchronization problems
Repairs/costs cited: Oil system issues implicated in lifter and camshaft failures requiring up to $10,000 repairs.
Recalls/TSBs owners mention: Recall references note engine oil problems in the L87 6.2L V8.
Emissions Control Module (ECM) light recurring
ECM warning light illuminates repeatedly on a diesel-powered Suburban, resetting to approximately every 8,000 miles. Dealership attributes to software issues but eventually identifies exhaust system leak. Warranty coverage disputed and customer fears GM has delayed addressing the issue until out of warranty.
When: Starting at approximately 20,000 miles, recurring at roughly 8,000 mile intervals through 61,000 miles
Symptoms owners cite: ECM light illumination; engine power reduction
Repairs/costs cited: Dealership performed multiple resets. At 61,000 miles, exhaust system leak identified but repair denied as non-warranty because it falls outside extended warranty coverage.
Recalls/TSBs owners mention: Dealership initially attributed to software issue requiring repeated resets; later identified as exhaust system leak.
Rear differential/axle grinding and failure
Rear axle produces grinding noise, typically when turning. Differential fluid replacement and figure-8 maneuvers did not resolve the issue. Vehicle does not appear in recall documentation despite well-documented issues in other 2021 Suburbans.
When: Mileage not specified
Symptoms owners cite: rear axle grinding noise; rubbing noise while turning; rear axle dragging in auto 4WD mode
Repairs/costs cited: Differential fluid replaced and figure-8 maneuvers performed but grinding persists. Dealer recommended rear axle replacement as next step.
Recalls/TSBs owners mention: Vehicle not included in recall despite being a well-documented issue in model.
Torque converter failure
Torque converter fails, causing rumbling, vibration, and shaking at speed. Diagnosed at independent service center without prior warning lights.
When: Failure occurred on 5/22/25 (approximately 93,000-100,000 miles based on complaint date)
Symptoms owners cite: rumbling when accelerating; vibration at consistent speed; shaking
Repairs/costs cited: Diagnosed as failing torque converter at independent service center; not repaired by time of complaint.
Uncontrolled acceleration with brake depressed
Vehicle accelerates on its own with brake pedal fully depressed, unable to stop. Driver had to shift to neutral and then park, then restart engine to regain control. Described as potential drivetrain electronics malfunction.
When: Complaint filed 7/19/2021
Symptoms owners cite: uncontrolled acceleration; vehicle accelerates despite brake depressed; high tachometer reading (approximately 5,000 rpm)
Repairs/costs cited: Diagnosis appointment scheduled but no repairs completed at time of complaint.
Multiple electrical and warning light failures
Vehicle displays numerous warning lights in rapid succession after tire change service, including transmission, driver window, ESC, windshield fluid, tire pressure, liftgate, forward collision system, battery/starter/connection issues, and check engine light. Vehicle eventually will not start.
When: Starting 5/3, with escalating issues through late May
Symptoms owners cite: transmission warning light; driver window warning; ESC warning; windshield fluid warning; tire pressure warning; liftgate open warning; forward collision system unavailable warning; battery/starter/connection warning; check engine light; vehicle will not start
Repairs/costs cited: Transmission flushed at dealership for $504. Multiple warnings reported but full diagnosis and repairs pending.
Vehicle becomes immobilized with inability to shift into neutral during traffic emergency
Vehicle fails to shift out of park or into neutral while stuck in the middle of traffic, creating a serious safety hazard. Tow truck had to drag the vehicle onto flatbed because it could not be moved. Dealership found lifter failure, bad starter, and bad fuse box.
When: Mileage not specified but described as 'less than' some threshold (exact mileage redacted)
Symptoms owners cite: automatic shift to park; cannot shift out of park; engine dies; cannot shift into neutral; lifter failure
Repairs/costs cited: Dealership identified bad starter, bad fuse box, and lifter failure. Lifter failure deemed unacceptable at low mileage.
Recalls/TSBs owners mention: Dealership commented they are seeing this lifter issue constantly from 2021 Chevy SUVs.
Valve body failure causing power reduction
Valve body in engine failed, causing loss of engine power and improper transmission shifting. Covered initially by extended warranty purchased at time of sale.
When: December (year not specified but vehicle purchased as CPO at ~119,800 miles)
Symptoms owners cite: engine power reduction; transmission not shifting properly
Repairs/costs cited: Covered by extended warranty ($2,500 paid at purchase).
Synthesized from 31 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 2 most recent
Has been in the dealer multiple times for very hard shifting issues. Jerks when shifting gears from stop or in lower speeds. They have tried everything and cannot figure it out. But the techs have felt it when driving as well. It has been doing it for a long time. And it’s a concern when driving, I do not feel safe.
I have a 2021 Chevy Suburban with the L87 6.2L V8 engine. At 7k miles, we have lost propulsion, leaving the car undrivable. resulted in the dealer replacing all 16 lifters under a recognized bulletin. I never received extended 6yr 100k mile powertrain warranty as described in the bulletin. Since then, There have been 3 other issues with loss of propulsion, resulting in replacement of fuel…
Had powertrain trouble with your 2021 Chevrolet Suburban?
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 Suburban?
It's a documented issue but not catastrophic. 31 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 31 complaints filed, powertrain issues most often appear around 78,200 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/Suburban.
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.