2020 Toyota Highlander: transmission slipping

Filed Oct 2, 2026 · Transmission · MS

• What component or system failed or malfunctioned, and is it available for inspection upon request? The UA80 8-speed automatic transmission assembly (specifically internal mechanical wear resulting from front carrier assembly bearing degradation/torque converter heat buildup). No, the component and the contaminated transmission fluid are currently being replaced at the dealership. • How was your safety or the safety of others put at risk? The severe mechanical wear and metal-on-metal degradation inside the transmission create an imminent hazard where the vehicle can experience sudden slipping, severe hesitation, or a complete, unexpected loss of motive power while traveling at highway speeds. This loss of acceleration in active traffic creates an immediate risk of a rear-end collision and leaves passengers stranded in an unsafe traffic pattern without warning. • Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. A professional diagnostic inspection confirmed that the transmission fluid was catastrophically low, and the assembly sustained severe internal damage via metal-on-metal contact with metal shavings actively circulating throughout the unit. • Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? The vehicle has been inspected and diagnosed by a service facility. It has not been inspected by the police or insurance representatives, as no crash has occurred yet. However, this failure directly mirrors the mechanical defects acknowledged by the manufacturer in Toyota Technical Service Bulletin T-SB-0008-21 and active federal class-action lawsuits. • Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? There were no electronic dashboard warning lamps or no electronic dashboard warning lamps or visible signs of prior leakage/seepage.

Filed Jun 26, 2026 · Transmission · NC

I am submitting this complaint regarding a sudden and unexpected transmission failure in my 2020 Toyota Highlander. The vehicle experienced a major transmission malfunction without any prior warning signs, dashboard warning lights, diagnostic messages, or noticeable drivability issues. The failure occurred suddenly when the vehicle would no longer shift into reverse. When placed in reverse gear, the vehicle does not move. Additionally, when placed in drive, the transmission slips significantly, resulting in a loss of power and unsafe operation. The vehicle is no longer reliable or safe to operate on public roadways. At no time prior to the failure were there any illuminated warning indicators, check engine lights, transmission warnings, abnormal noises, or other symptoms that would have alerted me to an impending transmission problem. The lack of warning created a hazardous situation, as the vehicle's ability to accelerate and maneuver could be compromised without notice. The vehicle has been diagnosed as requiring major transmission repairs or replacement, with estimated repair costs approaching $7,000. Given the severity of the failure, the absence of any warning to the driver, and the significant financial burden associated with the repair, I believe this issue may represent a safety-related defect that warrants investigation. I am concerned that other owners of 2020 Toyota Highlanders may experience similar sudden transmission failures that could result in a loss of vehicle control, inability to maneuver safely, or exposure to hazardous traffic conditions. I respectfully request that the federal safety agency review this matter and determine whether a broader investigation into transmission failures affecting 2020 Toyota Highlander vehicles is warranted.

Filed May 18, 2026 · Transmission · NE

Transmission failing/confirmed by dealer at 70k. No slipping, no warning messages, just whining prompted me to have it inspected. There are multiple lawsuits regarding these UA80 transmissions and Toyota is refusing to fix or acknowledge the manufacturing flaw.

Filed May 12, 2026 · Brakes · FL

My 2020 Toyota Highlander hybrid sometimes has a brake slipping or surging sensation when I apply my brakes while stopping. It happens periodically and not every time. I have not taken it to a Toyota service station for this specific reason but I mentioned it while in for a recent oil change. They checked for a recall but didn't find any. I have somewhat gotten accustomed to the issue and have been able to adjust. As I have stated, it doesn't happen every time I apply my brakes. My concern is if I allow someone else to borrow my car or even sell to a new owner. I believe I am the second owner.

Filed Nov 20, 2025 · Transmission · WI

While driving and/or accelerating you can feel some harsh shifts as well as slipping and shuttering with only 84k miles on this vehicle.

Filed Oct 7, 2025 · Transmission · FL

I am filing a complaint with the federal safety agency regarding persistent transmission slipping in my 2020 Toyota Highlander LE equipped with the UA80-E 8-speed automatic transmission. Since reaching approximately 55,000 miles, I have experienced noticeable slipping, characterized by delayed acceleration, erratic shifting, and occasional lurching, which align with documented defects in the UA80 platform as outlined in over 430 the federal safety agency complaints and Toyota’s Technical Service Bulletins (e.g., T-SB-0160-18 and T-SB-0008-21). These issues stem from a known manufacturing flaw involving a washer tab failing to secure the counter drive gear’s retaining nut, leading to gear movement, internal wear, and symptoms like mine. This defect, prompting Toyota’s Customer Support Program ZJC for 2017–2018 models and reported in later years like 2020, compromises vehicle safety and reliability, as slipping can cause unpredictable handling. I urge the federal safety agency to investigate further and hold Toyota accountable for addressing this widespread issue across affected models.

Filed Jun 13, 2025 · Body, Suspension · NH

It’s been a known issue that Toyota Highlander has transmission problems under 100k miles from 2016-2021 or later (social media sites confirmed such). My vehicle require a trans axle replacement as well as the struts are leaking oil and my vehicle has less than 62k miles and is only 5 years old. This is being covered under my extended warranty but parts are on back order After doing research many owners complain about a whining noise showing acceleration of vehicle . If left unfixed this leads to transmission gears slipping and eventually needing an entire replacement Some owners also complain about leaky struts. My car has an issue with leaky struts and is being fixed under warranty Some owners say they need an entire new transmission and after that is replaced the rear transaxle goes and needs replacement Toyota is not putting a recall on this but it’s a known issue. Owners are asking to have this put out as a recall by toy. All parts are on back order and takes several months before transmission can be repaired or replaced. This tells me there are hundreds if not thousands of Highlander’s having the same issue This is a Toyota problem and is related to building transmission in the factory..recall the older vehicles and do better in the factory

Filed Jan 6, 2025 · Transmission · CT

The transmission started slipping without any warning and then went into neutral while driving and I am not able to drive it anymore. The dealership said the transmission is bad. I see many complaints online about 2020 Toyota Highlander transmissions going bad for no reason. This is a new car only 4.5 years of normal driving and the transmission goes, this is not normal for such a high rated vehicle.