2017-2019 Colorado 8-speed TCC shudder is GM-acknowledged. Multiple repair visits may qualify California owners for a full buyback. Free review.
The second-generation Chevrolet Colorado was marketed as a mid-size truck that could do everything — capable off-road, comfortable on the highway, and refined enough to compete with full-size rivals. For thousands of 2017-2019 Colorado owners, the powertrain has delivered something different: a truck that shudders, shakes, and bucks at highway speed as though it is driving over rumble strips on an otherwise smooth road. The culprit is the 8L45 8-speed automatic transmission's torque converter clutch — and GM knew about it. Technical service bulletin 18-NA-355, filed with NHTSA and updated in July 2019, acknowledged that the shudder condition during light-throttle driving between 25 and 80 mph is caused by moisture absorption and degradation of the factory-fill automatic transmission fluid, which allows the torque converter clutch to shudder rather than lock cleanly. An earlier preliminary information bulletin (PIP5342B, August 2016) had already flagged shudder on 2015-2016 Colorado trucks with the same 8-speed family. GM's fix — a transmission fluid exchange with Mobil 1 Synthetic LV ATF HP — works for some owners and fails others. When the fluid exchange is insufficient, the TSB calls for torque converter replacement. A class action against GM over the 8-speed shudder defect was pursued through the federal courts before being decertified by the 6th U.S. Circuit Court of Appeals in June 2025. Decertification means the class cannot sue together, but individual lemon law claims remain fully viable — and for California owners, Song-Beverly is often a more effective remedy than class action litigation.
The issues owners report most, ranked by severity — each one verified against a cited NHTSA source.
Shuddering, vibration, or shake during light-throttle steady-speed driving between 25 and 80 mph; feels like driving over rumble strips or rough pavement; may also present as harsh downshifts from 2nd to 1st gear or slipping/bucking during acceleration; condition worsens after warm-up.
Sudden heavy or stiff steering, especially at low speeds or immediately after startup; steering wheel requires noticeably more effort to turn; warning light on instrument cluster; intermittent loss of power steering assist.
Soft or spongy brake pedal; brake warning light illuminated; visible brake fluid on the ground under the front wheels or on wheel faces; reduced braking effectiveness; brake fluid level drops without visible external cause.
Fuel smell from engine bay; check engine light; rough running or engine stall; visible fuel wetness under hood; in severe cases, underhood fire. May occur after a prior fuel pump service or at pump replacement.
No visible symptoms under normal conditions; seat belt may feel normal until a crash event. Recall identified through manufacturing quality audit.
Front passenger seat may rattle or feel loose; seat cushion may shift or feel unstable; no warning under normal driving, defect manifests under crash loads.
A settled Margarian Law case on this exact model, published with the actual settlement math.
Open any defect for the symptoms and why it matters for a California lemon-law claim. Each is tied to a cited NHTSA source.
Shuddering, vibration, or shake during light-throttle steady-speed driving between 25 and 80 mph; feels like driving over rumble strips or rough pavement; may also present as harsh downshifts from 2nd to 1st gear or slipping/bucking during acceleration; condition worsens after warm-up.
High lemon-law potential: widespread owner-reported shudder, multiple repair attempts with fluid exchanges and torque converter replacements, TSB-acknowledged defect, and a class action (decertified June 2025 at appellate level) involving this exact defect. Multiple unsuccessful dealer repair attempts documented in NHTSA complaints. Each fluid exchange attempt counts as a repair visit.
Transmission fluid exchange with Mobil 1 Synthetic LV ATF HP per GM TSB 18-NA-355; torque converter replacement if fluid exchange is insufficient. Some owners required full transmission replacement after repeated failures.
Sudden heavy or stiff steering, especially at low speeds or immediately after startup; steering wheel requires noticeably more effort to turn; warning light on instrument cluster; intermittent loss of power steering assist.
Safety-level defect. Two sequential recalls (16V054, 21V213) for the same root cause on the same model year — if a vehicle required multiple dealer visits for power steering loss this history supports a substantial-impairment claim under Song-Beverly. Total recall population: ~60,681 vehicles.
Dealers replace the steering gear torque sensor cover assembly (pinion sensor cover) at no charge under recall. Later recall expansion (21V213) covered additional 2015 MY units.
Soft or spongy brake pedal; brake warning light illuminated; visible brake fluid on the ground under the front wheels or on wheel faces; reduced braking effectiveness; brake fluid level drops without visible external cause.
Brake fluid leaks that increase stopping distance are a direct safety defect. If the dealer did not perform the recall remedy promptly or the condition recurred after the recall repair, this supports a lemon-law claim. 24,380 units affected.
Dealers inspect front brake calipers and replace as needed at no charge under NHTSA recall 15V278.
Fuel smell from engine bay; check engine light; rough running or engine stall; visible fuel wetness under hood; in severe cases, underhood fire. May occur after a prior fuel pump service or at pump replacement.
Fire-risk defect. Any Colorado with an open or recently remedied 18V358 recall that required dealer visits for fuel system concerns presents a strong basis for a Song-Beverly claim, especially if the vehicle experienced a fuel odor or check engine light before recall notification.
Dealers replace both the high-pressure fuel pump and the high-pressure fuel pipe at no charge under NHTSA recall 18V358.
No visible symptoms under normal conditions; seat belt may feel normal until a crash event. Recall identified through manufacturing quality audit.
Safety-critical restraint system defect. If a 2021 Colorado owner was not notified promptly or experienced a crash before the recall was performed, this supports a lemon-law or product-liability claim.
Dealers replace incorrect fasteners with proper specification bolts at no charge under NHTSA recall 20V811.
Front passenger seat may rattle or feel loose; seat cushion may shift or feel unstable; no warning under normal driving, defect manifests under crash loads.
Structural safety defect affecting occupant restraint. Small population (1,631 units) but serious consequence in a crash. If a dealer visit was required and the owner experienced seat movement or instability, supports a lemon-law claim.
Dealers inspect the front passenger seat cushion frame and replace it if it fails inspection, at no charge under NHTSA recall 22V375.
closed
The front passenger seat frame's hook attachment may not have been properly welded to the inboard track during two production shifts on March 22, 2022, when the laser welder power was inadvertently set too low at the seat supplier.
closed
Poor electrical connection within the steering gear assembly (corrosion or connector damage from manufacturing) may cause loss of power steering assist at startup or while driving.
closed
Incorrect bolts may have been used at one or more fastening locations to secure the seat belts to the vehicle structure.
closed
The joint connecting the high-pressure fuel pump outer housing to the mounting flange may not have been properly welded during a supplier manufacturing window (March 5-8, 2018). The weld may crack, allowing the pump to detach and oscillate, potentially damaging the high-pressure fuel line.
closed
Poor electrical connection within the steering gear torque sensor cover assembly may cause loss of power steering assist.
closed
Air pockets or a metal imperfection in the front brake caliper body may cause the front brake calipers to leak brake fluid.
Every item below comes from this vehicle's documented defects. The more you recognize, the more a free case review is worth your time.
California's Song-Beverly Consumer Warranty Act covers new vehicles purchased or leased in California. The law presumes a substantial defect when the manufacturer has made two or more unsuccessful repair attempts for a safety-related defect, four or more unsuccessful attempts for any other substantial defect, or the vehicle has been out of service for 30 or more cumulative calendar days during the warranty period. The 8L45 TCC shudder in the 2017-2019 Colorado is a GM-acknowledged defect (published in a service bulletin filed with NHTSA) that has required multiple dealer visits for many owners — some requiring fluid exchanges, torque converter replacements, and in some cases full transmission replacement. Each failed repair attempt counts. If you qualify, GM must repurchase your truck at the purchase price less a mileage offset, or provide a comparable replacement, and must pay your attorney fees if you prevail. The 6th Circuit's June 2025 decertification of the class action means individual lemon law cases under state law remain the most effective path for California owners. The above is general information and is not legal advice; results depend on the specific facts of your situation.
“Could not duplicate” doesn't mean the defect isn't real. Here's exactly what to do to protect a potential California lemon-law claim.
Document the moment it happens. Photos, video, and screenshots of any warning lights — with the date and the mileage.
Get a repair order every visit — even “found nothing.” That paperwork is the foundation of a claim.
Check your VIN at nhtsa.gov/recalls. Note any recall that has no available remedy yet.
Track your out-of-service days. California law counts the cumulative days your vehicle spends in the shop.
Keep loaner & rental records. Alternate-transport paperwork during long repairs matters.
Save everything in one place. Symptoms, dates, repair orders, and every repeat visit — the intermittent ones especially.
Many Colorado owners with the 8-speed shudder report a frustrating cycle: the truck shudders for weeks, then — on the morning of the dealer appointment — the condition is mild or absent. The dealer writes 'no trouble found' and returns the truck. The shudder returns within days. Under California law, that 'no trouble found' visit still counts as a repair attempt. Here is how to build a record that cannot be ignored: 1. Before every visit, record the symptom in detail: exact speed range, throttle position (light, steady cruise), ambient temperature, mileage, and whether the engine was fully warm. Video of the shudder through the seat or dashboard is highly persuasive. 2. Ask the service advisor to reference GM TSB 18-NA-355 specifically. If the technician is unfamiliar with it, point to the NHTSA document number MC-10163890 (the July 2019 filing). The TSB is publicly filed with NHTSA and identifies the shudder as a known defect requiring a specific fluid exchange protocol. 3. If a fluid exchange has already been attempted and the shudder returned, document that the TSB first-step remedy failed. The bulletin then calls for torque converter replacement. Push for it — or document the dealer's refusal to escalate. 4. For earlier 2015-2016 trucks, ask whether GM Preliminary Information Bulletin PIP5342B (August 2016) was applied. It predates TSB 18-NA-355 and addresses the same shudder on 2015-2016 8L45-equipped Colorados. 5. Retain all repair orders — CND visits, oil change records that note the shudder, loaner car arrangements, and any written communications from the dealer or GM customer service. Each document helps establish the timeline and supports the 30-day cumulative out-of-service tally under California law.
The 8-speed shudder on the 2017-2019 Chevrolet Colorado is one of the clearest patterns we see in lemon law cases involving GM trucks. GM's own technical service bulletin uses the phrase 'torque converter clutch shudder' and provides a documented repair sequence — meaning there is no legitimate dispute that the condition exists. When fluid exchanges provide only temporary relief and the shudder keeps coming back, the vehicle is failing to meet its basic warranty promise of delivering a durable, reliable drivetrain. If you have made two or more dealer visits for this issue without a lasting fix, a California lemon law evaluation is worth pursuing. The class action decertification in 2025 doesn't affect your individual rights — Song-Beverly was designed for exactly this kind of repeated, documented, unresolved manufacturer defect.
— The Margarian Law team
Has your 2017-2019 Chevrolet Colorado been shuddering on the highway? Has the dealer done a fluid exchange — and the shudder came back? Have you been in for the same problem two, three, or four times? California lemon law may entitle you to a full buyback or a replacement truck, with GM paying your attorney's fees. Get a free case review and find out if your Colorado qualifies.
If you own a 2017-2019 Chevrolet Colorado with the 8-speed automatic transmission (8L45, code M5T), the highway shudder between 25 and 80 mph at light throttle is a documented defect. GM issued technical service bulletin 18-NA-355 in June 2018, revised July 2019, specifically describing this condition as torque converter clutch (TCC) shudder caused by moisture absorption and degradation of the factory automatic transmission fluid. The TSB compares the sensation to driving over rumble strips on smooth pavement — which is exactly how most owners describe it. The bulletin applies to 2017-2019 Colorado trucks built before March 1, 2019. The first-step remedy is a transmission fluid exchange with Mobil 1 Synthetic LV ATF HP; if the shudder persists, torque converter replacement is the next step. An earlier GM bulletin (PIP5342B, August 2016) addressed similar shudder on 2015-2016 Colorados with the same 8-speed family.
Yes. GM filed technical service bulletin 18-NA-355 with NHTSA (document MC-10163890, updated July 2019) acknowledging that some 2017-2019 Colorado and Canyon owners would report a 'shake and/or shudder during light throttle acceleration between 25 and 80 mph,' describing it as the vehicle driving over rumble strips. The cause is identified as torque converter clutch (TCC) shudder from degraded factory ATF. No safety recall was issued; the bulletin directs dealers to perform a fluid exchange and, if unsuccessful, replace the torque converter. A class action against GM over this exact defect was filed in federal court and pursued for years before the 6th U.S. Circuit Court of Appeals decertified the class in June 2025. Decertification does not affect individual state lemon law claims, which remain a viable route for California Colorado owners.
A returning shudder after a fluid exchange is a documented second-step scenario under GM TSB 18-NA-355. The bulletin explicitly states that if the fluid exchange does not resolve the condition, the torque converter should be replaced. Go back to the dealer, reference the TSB, and document that the fluid exchange was an insufficient repair. Ask specifically for torque converter replacement — and get the request and the dealer's response on the repair order. From a lemon law standpoint, this follow-up visit is your second documented repair attempt for the same defect. If the torque converter replacement also fails to permanently fix the shudder, that is a third attempt. Under California's Song-Beverly Act, four unsuccessful repair attempts for a substantial defect — or 30 cumulative days out of service — creates a presumption that the manufacturer cannot repair the vehicle and entitles you to a buyback or replacement.
Yes. The 2015 Chevrolet Colorado is subject to two separate NHTSA recall campaigns for loss of electric power steering assist. NHTSA recall 16V054 (GM campaign 15595, January 2016, 2,988 units) was the initial campaign; NHTSA recall 21V213 (GM campaign N202325410, March 2021, 60,681 units) is a broader expansion covering 2015 Colorados and Canyons built before May 22, 2015. Both recalls share the same root cause: a poor electrical connection in the steering gear torque sensor, causing the power steering system to lose assist — sometimes intermittently, sometimes completely — particularly at low speeds where steering effort is highest. Consumer Reports covered the 21V213 expansion in April 2021. The remedy is dealer replacement of the steering gear torque sensor cover assembly at no charge. Check nhtsa.gov with your VIN to confirm whether both campaigns have been completed on your truck.
You may qualify. California's Song-Beverly Consumer Warranty Act covers new vehicles purchased or leased in California. The law presumes a lemon when the manufacturer cannot fix a safety-related defect after two attempts, cannot fix any other substantial defect after four attempts, or the vehicle has been out of service for 30 or more cumulative calendar days for warranty repairs. For Colorado owners dealing with 8-speed TCC shudder: if you have had a fluid exchange and the shudder returned, or if you have had multiple transmission-related dealer visits — fluid exchange, torque converter replacement, or full transmission work — each visit counts. The 6th Circuit class action decertification in June 2025 does not affect your individual California lemon law rights. If you qualify, GM must repurchase your truck at the purchase price less a mileage offset and pay your attorney's fees. Most California lemon law cases cost the owner nothing out of pocket. This is general information and not legal advice.
The 8-speed transmission class action against GM was not settled — it was decertified. In June 2025, the 6th U.S. Circuit Court of Appeals ruled that the case could not proceed as a class action, meaning there is no class settlement to opt into or compensation fund to claim. However, decertification of a class action has no effect on your individual lemon law rights under California's Song-Beverly Act. Individual claims are evaluated on their own facts — how many repair attempts were made, how many days the truck was out of service, and whether the defect substantially impairs the vehicle's use, value, or safety. For California owners with documented repair histories, an individual lemon law claim is often more effective than class action litigation and can result in a full buyback with attorney fees paid by GM.
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