2021 Toyota Highlander Powertrain (other) Problems

Transmission developed a whine at 61k miles. Needed to be replaced.

NHTSA ID

11766567

Incident

Sep 30, 2025

Toyota refuses to issue a recall for a well known issue with the UA80 transmission that fails around 5 years on many Highlanders. I follow [XXX] and there are countless posts about this issue. Mine failed at one month before my warranty was up and replacement was covered but it was replaced with the same transmission which I assume will also fail after 5 years or another 50,000 miles. There is a service bulletin for repair from Toyota so they're half admitting the issue but there needs to be a recall and a revision to the UA80 transmission to make them safer. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11766307

Incident

Jul 15, 2026

In my Toyota Highlander 2021 XLE model ,on 9/18 I hear a whinning noise when gas pedals is pressed. Took it to the Toyota TriCounty dealer in Limrick,PA for diagnosis. It was reported it is due to a transmission issue and it would cost around 10,600$ to repair. I haave been taking this vechile to same dealer to servie for last 5 years and this problem did not surface. I was told the car can be driven but would the car would stop when the transmission actually fails. Opened a case

NHTSA ID

11765895

Incident

Sep 18, 2026

Tech: SCOTT RICHART test drove vehicle performed inspection. Noise hear is coming from transmission internally. condition present is similar to condition described in T-SB-0008-21 for whine noise from transmission. Transmission would need replaced to remedy the noise. Vehicle is out of warranty, DOFU is 04/14/21. Transmission is not in the serial number range described in the TSB. Transmission serial # is A3A21C08858. QUOTED $8574.50 TO REPLACE TRANSMISSION WITH REMANUFACTURED TOYOTA TRANSMISSION.

NHTSA ID

11764197

Incident

Sep 14, 2026

Transmission Failure Yes TSB No Warning Lights

NHTSA ID

11764003

Incident

Sep 13, 2026

There is an unknown whine coming from the transmission when pressing on the throttle. It loud and high pitched.

NHTSA ID

11763567

Incident

Sep 11, 2025

Leadcar Toyota LaCrosse WI has diagnosed and reported that the transmission needs to be replaced. Pertains to Service Bulletin T-SB-0008-21 the pinion shaft bearing defect. The major powertrain component is failing prematurely. Cost to repair is over $9,000 as it is out of warranty. We purchased the vehicle at 67,550 miles on 3/29/2025. Since we never owned a Toyota before we thought the whining of the transmission was unique to that vehicle. Once we heard about the service bulletin we took it in to get diagnosed.

NHTSA ID

11763402

Incident

Aug 10, 2026

Transmission failure at 80,000 miles

NHTSA ID

11763132

Incident

Sep 9, 2026

transmission has failed. Toyota states: Toyota Technical Service Bulletin T-SB-0008-21 addresses a whining or grinding noise in select 2021 Toyota vehicles equipped with UA80E orUA80F automatic transmissions caused by a defect in the front carrier assembly pinion shafts. Yes it can be available for inspection. This can be repaired with a $12,000 new transmission. * Sudden loss of acceleration: You may press the gas and the vehicle doesn’t accelerate normally. This is particularly dangerous when merging onto a highway, crossing an intersection, or passing. How this toyota highlander is putting safety at risk: * Unexpected shifting or jerking: A failing transmission can slam into gear, hesitate, or shift unpredictably, potentially causing loss of control. * Loss of drive: The transmission may suddenly stop transferring power to the wheels. You could be unable to move forward even though the engine is running. * Getting stuck in a gear: If it goes into a “limp” or failsafe mode, the vehicle may be restricted to a single gear and have very limited acceleration. * Loss of power while already moving: If the transmission disengages unexpectedly, you can lose the ability to accelerate out of a dangerous situation. * Difficulty maintaining speed: On a highway or uphill, a failing transmission may suddenly stop providing adequate power. * Transmission fluid leaks: A significant leak can cause the transmission to lose lubrication and worsen rapidly. Depending on where fluid goes, it can also create other mechanical problems. * Unexpected engine RPM increases: The engine can rev very high without the Highlander gaining speed (“slipping”), which can leave you unexpectedly slow in traffic. * Being stranded in traffic: A complete failure can leave the vehicle immobile, creating a collision hazard if you’re stopped in a travel lane or on a shoulder. unknown if it has been inspected by anyone. There is no warning lights. Then only way you know is by a high whining sound.

NHTSA ID

11763069

Incident

Aug 24, 2026

The 8 speed automatic transmission (UA80E) in my 2021 Toyota Highlander Limited V6 FWD failed at 75,491 miles. The failure presented as a loud whining noise during acceleration between 30 and 40 mph. A Toyota dealership diagnosed complete transmission failure requiring full replacement of the transaxle assembly at a cost of $8,144.45 (repair order dated August 14, 2026). The dealership service manager confirmed in writing that the failure appears consistent with Toyota TSB T-SB-0008-21, issued February 9, 2021, which documented whine and grind failures of the front carrier assembly pinion shafts in this transmission family. My transmission was built in June 2021, after the serial range covered by that bulletin, and failed the same way, indicating the defect was not confined to the bulletin's production range. This transmission is the subject of multiple pending federal class action lawsuits alleging premature failure. A transmission failure of this type can result in sudden loss of power while driving, which is a safety hazard. The vehicle was purchased new from a Toyota dealership in July 2021, was maintained normally, and was never used under severe service conditions. The problem has been confirmed by the dealer. The vehicle and failed component are available for inspection and the vehicle remains at the dealership.

NHTSA ID

11762799

Incident

Aug 14, 2026

**Component/System:** Automatic Transmission — 8-speed (UA80E/UA80F), Toyota Highlander **Description of the problem:** My 2021 Toyota Highlander (approximately 116,000 miles) has developed a high-pitched whining noise a while ago, that occurs during acceleration, consistent with the symptom described in Toyota's own Technical Service Bulletin T-SB-0008-21 (issued Feb 9, 2021) for whine/grind noise in the transmission on this model. The vehicle has not yet been formally diagnosed by a dealer or independent shop as of this filing; I am submitting this report proactively given the volume of documented failures in this transmission platform and to add to NHTSA's record before the condition potentially worsens. I am aware, through Toyota's own TSB and multiple pending class-action lawsuits (including Pallaya v. Toyota Motor Sales U.S.A., Case No. 2:25-cv-10613, C.D. Cal., and LeBoutheller v. Toyota, Case No. 4:25-cv-01389, E.D. Tex.), that this transmission (UA80E/UA80F, used in 2017-present Highlander and related Toyota/Lexus models) has a documented pattern of premature failure nationwide, often presenting first as this same whining noise, and in a number of owner-reported cases progressing to sudden power loss, shifting into neutral, or stalling — creating a serious safety risk to occupants and other drivers, particularly at highway speeds.

NHTSA ID

11762480

Incident

Jul 1, 2026

At 57,000 miles the dealership says the transmission must be replaced. Toyota refused to replace it under warranty because they stated it wasn't serviced at Toyota consistently. There isnt a service for the transmission under 100k miles. This is a known issue with this transmission and they act oblivious to this issue.

NHTSA ID

11761897

Incident

Aug 19, 2026

The transmission whining started 70,000 miles and it is progressively gotten worse, there has been some sudden shifting at times. The manufacturer has known about this 8 speed transmission. Problem since 2017 and they haven’t done anything to improve it. Isn’t is something that the warranty only covers the drivetrain and. Transmission till 60,000. And know they are telling us that we have to pay anywhere from $7,000-$12,000 to,have it replaced. We have taken it to the Toyota dealership Thayer Toyota in bowling green,oh and they checked it out. And said that the front part of the transmission is ok it’s but the rear differential is the one that is going bad. We are hoping that there will an investigation on this UA80 transmission to see how many of the toyota models that have this transmission in it, have been reported and if any after the 60,000mile they have covered to be repaired at there cost. We understand that there is a CLASS ACTION LAWSUIT against this transmission. We would appreciate any help that you can get us. We can be contacted at [XXX] or phone number [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11761620

Incident

May 30, 2026

1. The car makes a squeaky sound when I accelerate. The faster I go the louder the noise becomes. I took the car to the Toyota dealership and was told that the transmission needs to be replaced. The car is only 5 years old. I checked online and noticed a lot of other people are also complaining about the same issue with their 2021 Toyota Highlander. 2. While driving on the Turnpike a few months ago, the driver side front door suddenly popped open on me. I had to hold it with my left hand, switched lane to pull safely to the shoulder lane in order to close it. The door was completely closed prior to this incident. When that happened, I was already driving on the road for over 1 hour. There was no previous signal that it was opened. It just popped open out of nowhere.

NHTSA ID

11761538

Incident

Aug 19, 2026

Toyota has known that the UA80 transmissions are faulty & they have not issued a recall. Mine failed at 60,500 miles just outside of the warranty period. I paid over $5,000 to have it replaced & the dealer confirmed that it required replacement due to a faulty transmission assembly. Toyota refuses to issue a recall or cover full costs for replacement.

NHTSA ID

11760864

Incident

Aug 14, 2026

It's about the problem with the automatic transmission UA80 already has the buzz That many customers are complaining sometimes it has jerks too.

NHTSA ID

11760076

Incident

Aug 27, 2026

The car's transmission is failing. •The "Whine of Death": The most common early warning sign is a high-pitched, airplane-like whining noise that rises in pitch with vehicle speed/engine RPM, especially once the transmission reaches operating temperature. •Technical Service Bulletins (TSBs): Toyota has issued internal bulletins (such as T-SB-0008-21 and related updates) addressing abnormal transmission noises and replacement protocols for affected V6 models. •No Formal Safety Recall (as of mid-2026): While the issue has spurred class-action lawsuits and high NHTSA complaint volumes, there has not been a mandatory safety recall for widespread replacement, leaving post-warranty owners to rely on goodwill assistance or third-party warranties.

NHTSA ID

11759926

Incident

Aug 1, 2026

At 66,000 miles the transmission on my 2021 toyota highlander is failing. This is a known issue with these transmissions and toyota is actively working against people to help get the parts replaced at their cost.

NHTSA ID

11759634

Incident

Aug 3, 2026

I made my last payment on my Toyota in June and the week I made my payment my mechanic confirmed a whining that had just started to be a transmission failure. After taking to another specialty transmission shop my transmission is failing. The internal bearings are failing just like the recall in other 2021 models. I’ve been told my VIN isn’t part of the recall but it is the same problem. I am having to pay $8500 on a transmission for a just paid off Toyota. I was so excited to be debt free. This is unacceptable. A Toyota transmission should not fail the minute it’s paid off. I’m very disappointed in Toyota. I contacted the dealership and the warranty help team to try to get part or all paid for and got nowhere. My car needs to be included in the recall of Highlanders with the internal bearing failure.

NHTSA ID

11758572

Incident

Jun 1, 2026

Bought my 2021 Toyota Highlander XLE AWD 3 years ago due to supposed safety and reliability. Transmission went out right after warranty at 64,000 miles. Was not made aware that this is a common issue. Vehicle hard shifted and suddenly lost power when driving home with my 4 year old while making a left turn, and we were almost hit by oncoming traffic. Have not had prior issues in the past to suspect this would happen, so it was very sudden and unexpected. There has been no recalls or awareness for this which could have seriously injured my child and I. Went to take it to the closest mechanic right away to troubleshoot since the vehicle was not throwing any codes.

NHTSA ID

11758405

Incident

Aug 20, 2026

This vehicle experienced transmission failure at 43,000 miles. There is a technical bulletin regarding a known manufacturer defect for this Make/Model/Year (TSB-008-21) and we were told by our Toyota service technician that our vehicle displayed all of the same symptoms as those identified in the technical bulletin. Unfortunately the serial number for our vehicle was not included in the bulletin and we were four months outside of the power train warranty, therefore Toyota refused to cover the costs of replacing the transmission. We are requesting that TSB-008-21 is reviewed and expanded to cover additional vehicles including ours that were affected by this manufacturer defect that caused both a safety risk as well as a financial hardship for our family.

NHTSA ID

11757967

Incident

Jul 8, 2026

At around 75000 miles (less than 5 year old vehicle) the transmission exhibited a noticeable whine. After further research I presented the vehicle to the local Toyota dealer service department. An active technical service bulletin T-SB-0008-21 that describes a manufacturing defect with the front carrier assembly pinion shaft (essentially a catastrophic transmission failure) was matched to the symptom the vehicle was exhibiting. Further, my transmission serial number is directly within the affected production defect list. Failure to replace this transmission at significant cost (should not normally be routine maintenance on a highway driven vehicle at this age and mileage) could result in total loss of power and control causing the potential for a severe traffic hazard or accident.

NHTSA ID

11757911

Incident

Jul 1, 2026

My transmission started to have a noticeable whine at 53k miles. It became noticeably louder during acceleration. It was diagnosed at the Toyota dealership as a failing transmission. My vehicle was a few months out of warranty. I was told to contact Toyota corporate to ask for assistance. I was told since I did not have a service record at the dealership, they would deny my claim. I advised them the transmission was a sealed unit with no dipstick. My vehicle has been meticulously maintained with records. They said sorry, and the conversation ended.

NHTSA ID

11754750

Incident

Dec 31, 1969

Vehicle is experiencing a distinct, high-pitched mechanical whine or grind sound from the transmission during acceleration that increases in pitch with vehicle speed. The noise does not happen while cruising or coasting. This symptom aligns directly with Toyota Technical Service Bulletin T-SB-0008-21 ('Whine or Grind Noise From Transmission'). I am concerned about a premature, catastrophic internal bearing or gear assembly failure of the UA80 8-speed transmission while driving at highway speeds, which poses a severe sudden loss of propulsion safety risk.

NHTSA ID

11754631

Incident

Apr 6, 2026

High pitched whirring from engine when accelerating. Took to mechanic who diagnosed worn internal transmission bearings that could lead to transmission failure. No warning lights or indicators. Toyota is aware of this issue (see Toyota Technical Service Bulletin T-SB-0008-21) but is doing nothing in response.

NHTSA ID

11754021

Incident

Jul 23, 2026