2021 Toyota Highlander transmission problems

Filed Nov 6, 2026 · Transmission · IA

There is Powertrain - Transmission failure on my 2021 Highlander V6 8 speed with just over 50,000 miles. Toyota is aware of transmission failures with the Highlander family of vehicles equipped with the UA80 transmission. The failure with the UA80 transmission can cause a sudden power loss in traffic which escalates it to a safety issue. My Vehicle has been inspected by the Toyota dealership and confirmed to be well-maintained. Transmission failure confirmed by dealership and documents have been shared with Toyota Corporate (Toyota Motor North America). Toyota is refusing to take any responsibility, cover any cost associated, or do any recall, putting their consumers and others at risk.

Filed Nov 5, 2026 · Transmission · TN

The transmission started whistling around 66k miles. It was diagnosed by 3 different dealerships, including Toyota, as a transmission failure. It was diagnosed as a known issue with this year Highlander, with no fix on the market. I am having to pay $10k out of pocket because this is out of warranty by 6k miles. Highly dissappointed.

Filed Nov 4, 2026 · Transmission · MI

**Component:** The 8-speed automatic transmission (Aisin UA80F, AWD) failed internally. A Toyota dealer test-drove the vehicle on 10/09/2026 and verified the noise comes from transmission internals. The repair order states: "Internal transmission failure causing whining noise while driving/accelerating." **Safety risk:** The transmission is failing internally and has not yet failed completely; if it does while driving, it could cause a sudden loss of motive power. I am reporting it because the same failure mode is documented in Toyota service bulletin T-SB-0008-21 (front carrier assembly pinion shafts), but this transaxle — serial A4A20M 00395, built at TMMWV in December 2020 — is immediately outside the bulletin's affected range (A4A20L00101–A4A20L01824, November 2020). It failed identically, which suggests the November 2020 production change did not fully correct the defect. **Inspection:** A Toyota dealer confirmed the failure by test drive and inspection. Toyota (the manufacturer) has not inspected the vehicle. No police or insurance inspection. **Symptoms:** A whine at all speeds. No warning lamps or messages. No crash, injury, or fire.

Filed Nov 4, 2026 · Transmission · IL

I purchased my 2021 Toyota Highlander AWD brand new in March 2021. In May 2026, at approximately 120,000 miles, I began hearing a high-pitched whining noise coming from the transmission. The noise became louder as I accelerated. Toyota disregarded the noise and advise that it was normal due to the mileage of the vehicle In August 2026, I took the car back to perform an oil change and tire rotation and I mentioned once again the noise coming from the transmission, Once again the dealer told me that i was due to the mileage. I took the car in October 26 to perform oil change and tire rotation and I mentioned the noise again. The dealer then made an appointment to inspect the issue Toyota dealership technicians inspected my vehicle and diagnosed failing transmission bearings. Toyota confirmed that the transmission needs to be completely replaced. The estimated replacement cost is $9,500. I am concerned about the safety risk because a failing transmission can potentially cause loss of power, unexpected changes in vehicle movement, or difficulty accelerating while driving in traffic. I am concerned that the condition could worsen and create a dangerous situation for me, my passengers, and other drivers. The first symptom was a high-pitched whining noise that began in May 2026 at approximately 120,000

Filed Oct 29, 2026 · Transmission · PA

My 2021 Toyota Highlander XLE began making a high-pitched whining noise when accelerating. When researching this noise, associated with the make, model, and year of my vehicle, it became apparent that the noise is associated with a manufacturer's defect in the [XXX]‑speed transmission (Toyota [XXX]). The cited notification states that the correction for this defect is a transmission replacement that is only covered by the 60,000 mile/5 Year warranty. There are three class-action lawsuits associated with this issue, and I wanted to document my incident in the event that my service appointment with [XXX] Toyota in [XXX], on 11/23/2026 indicates that my transmission is affected by the defect so many have experienced. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 22, 2026 · Transmission · PA

I recently purchased a 2021 Toyota Highlander Platinum. Within a few weeks from purchase, the transmission started making a whining noise. Upon further research, it was discovered that Toyota has been installing the UA80=F transmission in their vehicles, knowing full well that there are serious issues with this particular transmission. But yet they continued using this transmission. Someone needs to address this issue and hold their feet to the fire.

Filed Oct 9, 2026 · Transmission · 70,100 miles · PA

The contact owns a 2021 Toyota Highlander. The contact stated that while driving at an undisclosed speed, there was a loud high-pitched whining sound coming from the vehicle. The contact stated that the vehicle hesitated while accelerating and the transmission was shifting rough. The contact stated that the vehicle had experienced an internal transmission failure. The manufacturer was notified of the failure. A local dealer was contacted and associated the failure with Toyota Technical Service Bulletin: 0008-21. The contact stated that a diagnostic test was scheduled. The failure mileage was 70,100.

Filed Oct 6, 2026 · Transmission · NJ

Noticed a whine noise slowly progressing over a couple of weeks. Researched the sound and took it for diagnostic eval. with Holman Toyota in Mt. Laurel, NJ on 10/3/2026. As suspected, the transmission is failing. Mechanic documented via video the fluid sample containing suspended metallic particles with discoloration and burnt odor. They also verified the whining sound coming from the transmission. This is a known failure for the 2021 highlander with a TSB bulletin. Although they have yet to place a recall. There were no warning messages. The complete failure of a transmission while driving could cause sudden immobilization and most certainly result in an a motor vehicle accident. The vehicle has under 54,000 miles and is about 10 weeks outside the warranty.

Filed Oct 4, 2026 · Transmission · NE

65K miles on the vehicle and have started to get a whining noise from the transmission during acceleration. UA80F transmission installed with multiple class action lawsuits against Toyota for this issue as it leads to catastrophic failure with high replacement cost. Stopped driving the vehicle and looking into transmission replacement options. Toyota needs to be held liable for mechanical defects.

Filed Oct 4, 2026 · Transmission · MO

We bought a 2021 Toyota Tacoma Platinum in November 2020. In February 2021, Toyota issued a Technical Service Bulletin T-SB-0008-21. The bulletin say transmissions may exhibit a whine or grind noise from the transmission. This condition may be caused by an issue with the front carrier assembly pinion shafts. This bulletin says repair is covered under the Toyota Powertrain Warranty. This warranty is in effect for 60 months or 60,000 miles, whichever occurs first, from the vehicle’s in-service date. Our transmission began making this noise around 75k miles, outside the warrant. Toyota knew about this problem over 5 years ago and did not take action to recall it. Now this repair is going to cost between $9,000 to $12,000 out of pocket. I cannot afford this repair. I have uploaded the bulletin from Toyota.