2020 Toyota Highlander Powertrain & Transmission Problems

The transmission started making a whining noise around 69,000 miles that a mechanic said was due to transmission failure. There were no warning lights or messages. I took it to the Toytota dealer who sold it to me new. They inspected it and confirmed that the transmission needed replaced which they did. Online research said these symptoms meant the transmission could fail at any time while driving it which could put passengers and others at risk.

The transmission had a catastrophic failure at 73,000 miles and six years after purchase. There has been a service bulletin issued with known defects on this transmission yet Toyota corporate failed to acknowledge that they installed faulty transmissions in the 2020 Toyota Highlander. The diagnosis was a failed pinion bearing which the dealer diagnosed to replace the transmission at nearly $10,000

My 2020 Toyota Highlander XLE AWD developed a high-pitched whining noise from the drivetrain/transmission area while accelerating. The noise increases under acceleration and stops when the accelerator is released. The noise is not present when the vehicle is in neutral. I brought the vehicle to an authorized Toyota dealership for diagnosis. The dealership confirmed the condition and determined that the transmission requires replacement. The vehicle had only recently exceeded 60,000 miles when the problem was diagnosed. My safety concern is that this appears to be an internal transmission failure occurring at relatively low mileage. Because the transmission is a major drivetrain component necessary to maintain propulsion, I am concerned that continued deterioration could result in loss of propulsion or a more serious transmission failure while the vehicle is being driven. Toyota has reviewed the dealership's diagnosis and has approved supplying a replacement transmission through goodwill assistance. The original transmission has not yet been removed and remains installed in the vehicle. I am reporting this condition because I have identified other complaints involving Toyota Highlanders with similar transmission whining under acceleration and subsequent transmission replacement. I am concerned that this may represent a recurring transmission defect rather than an isolated failure. Because the original transmission is still installed, the vehicle and transmission should currently be available for inspection by NHTSA or other appropriate parties if requested before the repair is performed.

We have a 2020 Toyota Highlander with 89K miles that we have owned since it was new. I was informed today to not drive it any long distances from the dealer due to an impending failure of the transmission, creating a large safety issue for me and my family. I understand there are related recalls of the UA80 transmission but none for this particular model; there are countless internet reports of failure. I implore the NHTSA to investigate and protect the motoring public.

The transmission can suddenly fail even at very early mileages. This is almost certainly related to T-SB-0008-21 that has defined a narrow number of transmissions though it appears to affect many more than outlined. This could cause sudden failure while operating the vehicle at any point in time and potentially lead to a crash without much if any warning. Toyota Brand Engagement is denying any assistance due to external service history from a prior owner rather than addressing the failed part outlined in the TSB. Failure reasoning cannot be provided from the dealership as Toyota does not allow the dealer technicians to open the transmission and instead mandate a full replacement.

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 NHTSA review this matter and determine whether a broader investigation into transmission failures affecting 2020 Toyota Highlander vehicles is warranted.

Transmission stalls in situations where speed is needed. For example when merging into traffic all of a sudden no power then when gear finally engages there a huge thump and feels like being hit from behind.

The transmission (the UA80) has been known to have several issues and my transmission has normal driving on it, has had its fluids replaced, and is now experiencing the same issue that others are experiencing.

The 8 speed Toyota transmission is defective and my transmission started to whine very loudly. I was told that it could freeze/lock up on me at any time so I had a rebuilt transmission put in my car. I am told Toyota new about this defect.

My transmission failed in my 2020 Toyota Highlander after about 75,000 miles. This is a know issue technical service bulletin # T-SB-0008-21. The dealership acknowledged the known issue and instructed me to reach out to Toyota corporate for goodwill assistance which I did. They are reviewing my case but told me that they will not replace the transmission even thought its a know issue. It will be $10,000 dollars to repair.

My 2020 Hylander, which has under 50,000 miles, started to whine with any use of gas pedal/acceleration. None of the warning lights were triggered. My mechanic informed me today it needs a new transmission, and for safety reasons, the car shouldn’t be driven. I’ve been reading how there are known problems with Toyota’s transmissions for my age car—this is negligence on their part—these cars should be recalled and fixed by Toyota.

The transmission has been making a whining noise since about 75K miles. Had the transmission fluid changed at about 110K miles. Still makes whining noise and now has a rumble occasionally. We took it to the dealer and they said the transmission needs replaced. Over $8k in charges for the repair.

Toyota Highlander UA-80 transmission failed prematurely at 63,017 miles (just beyond warranty) due to KNOWN CRITICAL manufacturing defect as per technical advisory T-SB-0160-18 putting me and my family at risk for sudden catastrophic failure on the highway.

The contact owns a 2020 Toyota Highlander. The contact stated that while driving to the dealer for a service appointment, the vehicle made an abnormally high-pitched sound. The vehicle was diagnosed with a UA80 transmission failure. No further information was available. There was no warning light illuminated. The manufacturer was notified of the failure. The failure mileage was approximately 71,233.

I took my car in for service and I noticed my car is making a loud whining noise. I asked the mechanic about it and he said my transmission is going out. I found on the web several people complaining about the 8-speed Toyota transmission and how it will stop working shortly. The complaints are numerous and it listed all the of the technical bulletins that Toyota issued and they knew about the problem years ago. I am taking my car to shop to have it fixed or replace. Based upon all my research, I am concerned that the car will stop working and leave me in an unsafe situation. I am not happy that Toyota is selling such a defective product.

The vehicle recently began making a whining noise when the gas pedal is pressed that is consistent with premature failure of the transmission. I took it to my local dealership and they recommended replacing the transmission and limiting usage of the vehicle to short trips until that is done because the transmission could fail while driving which would result in loss of power to the wheels which could lead to an accident.

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.

The transmission failed. It is available for inspection. Should the transmission have completely failed on the road, it could have lead to an accident. Per the dealership diagnostic: replace transmission and torque converter assembly with applicable seals due to internal transmission failure. It has not been inspected by anyone else. No warning lights. This is a widespread problem in 2017-2020 Toyota Highlanders. Failure frequently happens right after the expiration of the manufacturer warranty and Toyota refuses to pay for it.

This Toyota Highlander make whining sound when I try to speedup, even a little bit. I had a transmission shop checked, and I was informed there is metal pieces in transmission fluid. I am concerned it will break one day on highway while driving.

The transmission failed after 56,000 miles. Based on the research this UA80 transmission has a lot of problems and Toyota has issued TBS and even extended warranty for the previous year models in the past. The transmission failed right after the time allowance for the 5 years 60,000 mile powertrain warranty, but within the mileage.