2020 Toyota Highlander Powertrain & Transmission Problems

My 2020 Toyota Highlander experiences transmission jerking and hesitation during low speed acceleration. The issue was first reported to the dealership while under warranty but was not diagnosed. The vehicle now requires transmission replacement 7k miles over the warranty despite the issue being reported during the warranty. Toyota has refused a repair under warranty and has violated their terms of powertrain warranty. This 8 speed transmission commonly has issue during production years 2017-2022 and toyota has admitted to a production defect. Despite that they have refused a goodwill repair or a warranty repair.

1. The vehicle’s transmission appears to be failing. I was driving my 2020 Toyota Highlander on the freeway at about 75 mph with my family in the vehicle when the car suddenly lost power and would not accelerate properly even though the engine was still running. Because of the sudden loss of power, I had to carefully move the vehicle to the shoulder of the freeway. At the time I did not realize it may have been related to the transmission. 2.Recently I brought the vehicle to an authorized Toyota dealership for a routine oil change and because I had started hearing a whining noise when accelerating, especially above about 30 mph. After inspecting the vehicle, the dealership informed me that the transmission needs to be replaced and provided a repair estimate of approximately 9,800. The vehicle currently has around 72,000 miles and the transmission is available for inspection upon request. 3.The sudden loss of power on the freeway created a dangerous situation because traffic around us was moving at highway speeds. My family was in the vehicle and I had to maneuver the car to the shoulder while vehicles were passing at high speed, which could have resulted in a serious accident. 4.The issue has been confirmed by the authorized Toyota dealership service department. When the incident occurred and we were stopped on the shoulder of the freeway, we contacted the highway patrol because we were concerned about our safety while stopped on the highway. 5.No warning lights or messages appeared on the dashboard prior to the loss of power. The only symptom noticed before bringing the vehicle in for service was a whining noise during acceleration.

Vehicle: 2020 Toyota Highlander XLE Purchased: August 2020 Owner: Original owner Transmission: UA80F Dealer quote for “Transmission assembly remove and replace: $8,666.22 +tax The vehicle is experiencing delayed acceleration (lagging power) and a loud whirring noise from the transmission when the accelerator pedal is pressed. The whirring noise immediately stops when the accelerator pedal is released. The Toyota Highlander had just exceeded the 60,000 mile/5 year powertrain warranty. Vehicle has 68,079 miles and is 5 1/2 years old. The delayed acceleration creates a serious safety hazard, particularly when starting from a complete stop while attempting to make a turn into traffic. On multiple occasions, the vehicle failed to respond promptly when the accelerator was pressed, placing the vehicle at risk of being struck by oncoming traffic. On February 17, 2026, Oakbrook Toyota diagnosed the vehicle with a failed/bad transmission after charging a $200 diagnostic fee to investigate the whirring noise and power delay. This failure occurred on a vehicle that has been properly maintained and has not been modified. Upon searching the Internet, there are many, many complaints regarding the UA80 transmissions failing between 60,000 and 70,000 miles. There are also multiple lawsuits filed for failed transmissions.

My 2020 Toyota Highlander, with 83k miles, started making a whining noise when accelerating. I took the vehicle to a local auto shop and they advised there was a transmission issue. There were never any warning signs of issue. I then took the vehicle to Antwerpen Toyota in Clarksville, MD (where the vehicle was purchased) and paid $185 for a diagnostic appointment. On February 20, 2026, The dealership provided a written estimate for “Replace automatic transmission assy” with a total cost of $9,403.77. I am very concerned for the safety of myself and others continuing to drive the vehicle without proper repair. The vehicle is otherwise in great condition and I keep up with all regular maintenance.

THE TRANSMISSION FAILED SUDDENLY.

Transmission is presenting a high-pitched whining noise.

Our 2020 Highlander with 45,000 miles started making a whining noise when accelerating. After the Toyota garage looked at it we were told that we needed a full transmission replacement. No warning lights came on alerting of us of problem. We were also told by the service depart that they are not surprised there hasn’t been a recall due to how many transmissions they have replaced on these vehicles and especially this type of transmission. Upon researching this particular issue, It is a wide known issue with class action lawsuits. New transmissions are also only carrying a 1 year warranty. That is hardly a warranty on a costly repair. It will cost us out of pocket $8,000 for a vehicle that is meticulously maintained and with only 44,000 miles. These vehicles are still being sold putting myself, my family and many more Americans as risk.

Whine noise when you accelerate coming from the automatic transmission. Car is hesitant in shifting gears when needing to accelerate causing safety issues/concerns while driving due to the inconsistency. Toyota dealer as inspected the vehicle and recommended a transmission replacement. Dealer has filed a claim with Toyota to see if it will be covered or not. Total price of repair quoted from dealer was $8700.00. I am also being told there is a back order on parts related to the repair of the vehicle and that the amount of vehicles with this issue are increasing in numbers each day. I purchased this vehicle new in 2020 and have been the sole owner.

Transmission stutters. Only has 32000 miles.

Transmission whines in low gear.

TRANSFER CASE MAKING ROTATIONAL BEARING NOISE FLUID HAVE LOTS OF METAL DEBRI

Transmission malfunction that left us on the highway with no power and in an unsafe situation. Not confirmed as of yet. At dealership tomorrow. No inspection completed by parties listed above. Check engine light appeared prior to malfunction.

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

The vehicle’s automatic transmission (power train) has developed a loud whining/whirring noise under acceleration. This noise increases with engine load and indicates internal mechanical failure. The transmission is still installed in the vehicle and is available for inspection upon request. This issue poses a safety risk because it causes hesitation and unpredictable acceleration behavior while merging or crossing traffic. There is also concern that the transmission could suddenly fail while driving, resulting in loss of propulsion and potentially causing an accident. The problem has been inspected and confirmed by a Toyota dealership, which advised that the entire transmission needs to be replaced at a cost of over $8,000, despite the vehicle having only approximately 77,000 miles. The vehicle has been inspected by a Toyota manufacturer service center. They identified the transmission failure but stated there are no current recall programs covering this specific VIN. No warning lights or error messages were displayed at any time before or during the failure. The first noticeable symptom was the transmission whining/whirring noise during acceleration, which began around 77,000 miles and continues to worsen.

My 2020 Highlander developed a whining or grinding noise consistent with the Technical Service Bulletin. I took it to a Toyota Dealership for diagnostic and they confirmed the whining and hissing sound. They said it would cost $9,000 to repair. I called Toyota to request a goodwill repair and they denied me. Toyota case number: 251229000423. The car does not feel safe to drive. We worry that at any moment the car could break down with our children inside. The problem was reproduced at a dealer and inspected. There were no warning lamps or messages, just the obvious sound coming from the transmission.

Transmission failure. Noticed whining when driving, took to local Toyota dealership and they diagnosed transmission failure. They quoted $12,000 for transmission replacement and confirmed that this is a known issue with certain years/models of Toyota Highlander. Ours is a 2020.

At approximately 120,000 miles, the vehicle began exhibiting a pronounced shudder or vibration between 40–50 mph under light acceleration or steady cruising. The condition progressed to delayed shifting and intermittent loss of acceleration response. The most concerning issue is hesitation and reduced acceleration when attempting to merge into traffic or increase speed. On multiple occasions, the vehicle failed to respond promptly to throttle input, creating a potential safety hazard due to loss of propulsion. The vehicle was evaluated at two authorized Toyota dealerships. Both indicated that the condition is consistent with torque converter or transmission failure. Full transmission replacement was recommended at an estimated cost of approximately $9,000. No whining or grinding noises are present; symptoms primarily involve shuddering and hesitation. The vehicle has not been driven since October 21, 2025, due to safety concerns and to prevent further damage. The vehicle has been regularly maintained at Toyota dealerships and has not been used for towing. This complaint concerns loss of acceleration, transmission shudder, and potential premature failure of the 8-speed automatic transmission.

The car started making whining noises when pressing the gas pedal. Toyota reported "noise from transaxle final drive. recommend replace. vehicle ok to drive but noise will continue until transaxle is replaced." There are no warning lights, messages or other symptoms prior to the sound starting or currently. This is a known issue with its 8-speed automatic transmission (UA80E/UA80F) that can cause whining, erratic shifting, and premature failure. This issue is the subject of a Customer Support Program (CSP ZJC) and several lawsuits, but the program has limited coverage for VINs, leading to owner complaints about a lack of assistance from Toyota.

I am filing a complaint with the NHTSA 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 NHTSA 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 NHTSA to investigate further and hold Toyota accountable for addressing this widespread issue across affected models.

UNKNOWN, dealers are reporting 1-2 2020-2022 Highlanders are needing completely transmission replacements at 8-10k in cost. They are all failing and toyota knows this.