2021 Toyota Highlander Powertrain (other) Problems

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

This vehicle was purchased new in 2021 with 4 original miles. Today it has 58,000 miles and has been maintained, per manufacturer recommendations, a certified Toyota dealership. At around 56,000 miles we noticed a slight whine in first gear. This was attributed to normal noise that we simply had not noticed. by 58,000 miles the while had extended to all gears and become more prominent. Research online shows that this is a known issue with the UH80 transmissions and has been since at least 2017. Toyota has a TSB for it (TSB-0008-21). This was not mentioned at the time of purchase or any of the various maintenance appointments in the last 5 years. This KNOWN issue WILL lead to complete transmission failure. This can happen while parked or in motion and can include the transmission shifting out of an active gear, locking into a gear and being unable to shift to another or park/neutral and there is no way to avoid it. I called Toyota corporate about this because I was not made aware of the TSB until July of 2027 and was advised that, although I was below the 60,000 mile allowance, I had surpassed the 60 month coverage period by two months and would not be granted a warranty exception (Toyota case number: 260710000821). Due to a known defective part on a vehicle that Toyota sold without advisement of said known issue, I am expected to pay $8,000 in repair fee's for a 40,000 dollar car that I have already spent over $20,000 on. The dealership confirmed the issue on 7/28/2026 and are attempting to use my 3rd party warrant which only covers parts. I will still be expected to pay for the labor costs which they expect to land between 2-3k dollars. Toyota is knowingly allowing a defect to persist that puts their customers and anyone else on the road at the time, at risk of serious injury and death. They expect their customers to cover the cost of repairs for an issue that they were aware of at the time of sale

NHTSA ID

11753805

Incident

Jul 28, 2026

The contact owns a 2021 Toyota Highlander. The contact stated that while driving 25 MPH, there was an abnormal whining sound coming from the engine. The vehicle was taken to the dealer, where it was diagnosed with transmission failure due to a pinion shaft failure. The dealer determined that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 62,300.

NHTSA ID

11753484

Incident

Jun 29, 2026

Mileage

62,300 mi

The transmission has failed due to a defect within the transmission. Toyota is aware of the defect but refusing to assist owners claiming warranty expiration despite the transmission failure occurring due to a defect and not normal wear and tear. Toyota service bulletin accepting the defect. T-SB-0008-21

NHTSA ID

11752018

Incident

Jul 16, 2026

The contact owns a 2021 Toyota Highlander. The contact stated that the vehicle was taken for oil filter maintenance and a spark plug change, and after the maintenance, the vehicle made an abnormal sound each time while accelerating. The dealer was contacted and diagnosed the vehicle with transmission failure. The vehicle was not yet repaired. The manufacturer was contacted and stated that the vehicle was out of warranty. The failure mileage was approximately 59,000.

NHTSA ID

11751494

Incident

Jun 23, 2026

Mileage

59,000 mi

I bought the vehicle used from a Cadillac dealer in Orlando with 72700 miles on it. At approximately 75000 miles my wife and I noticed a faint whine coming from somewhere. As it worsened, I researched the issue to find that Toyota has a TSB for a manufacturing defect in the transmission. As I understand it, the transmission can fail suddenly causing a serious safety concern. I need to fix this problem as soon as possible for my family’s safety but since I am out of the warrantee period and there are class action law suits in progress I am starting here. The cost of the repair, I am told will be $9000 a $11000. There should be a safety recall for this.

NHTSA ID

11751011

Incident

Jun 5, 2026

My 2021 Toyota Highlander Platinum is experiencing a transmission issue consistent with a known problem affecting the UA80 eight-speed transmission used in 2020–2024 Highlander models. The vehicle is currently at Greentree Toyota in [XXX] for diagnosis. This failure is occurring at 63,913 miles, only about 3,900 miles past the vehicle's 60,000-mile powertrain warranty. I have opened a case with Toyota (Case #XXX) and am requesting this be documented as part of a broader pattern reported by other 2020–2024 Highlander owners, including other 2021 Platinum trim owners INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11750009

Incident

Jul 13, 2026

Our Transmission is failing on our 2021 Highlander. It has a little over 76,000 miles on the vehicle. 2021 and 2022 seem to have many issues with the transmission failing. The dealership's estimate is almost $11,000! We only buy Toyotas and never had this issue with our Sequoia, sienna, avalon, Rav 4 with lots of miles and never needed a new transmission!

NHTSA ID

11749504

Incident

Jun 13, 2026

A known issue with this transmission. It started whining and had to be replaced at around 40,000 miles. Was replaced with a rebuilt transmission instead of a new one.

NHTSA ID

11749339

Incident

Apr 14, 2025

The Automatic transmission is making a whining noise when you press the accelerator. I took it to the dealer and they confirmed it needs a new transmission. the vehicle started making noise at 58,000 miles. When I was able to bring it in it had 60,200 miles on it. They would not cover it under warranty because the 5-year portion of the warranty was up a few month prior. I filed for a goodwill replacement with Toyota and they denied me. Dealer estimate for a replacement was over $8,100 dollars. No warning lights, the problem started with a gentle hum or whine much like a bad pulley bearing then got progressively worse.

NHTSA ID

11749252

Incident

Apr 3, 2026

Experiencing high pitched whine noise at approximately 65k miles. Local Toyota dealer test drove vehicle, also noticed high pitched whine, and diagnosed as transmission going bad due to issues noted in T-SB-0008-21. Transmission can fail without warning at any time and leave driver stranded or in dangerous traffic conditions with inability to shift gears correctly to get out of harms way.

NHTSA ID

11748658

Incident

Jun 22, 2026

at 109,000 miles the car started having a whining sound with accelerating. When inspected by the Toyota dealer were told we would need a new transmission. Upon further searching there have been many many reports of transmission failure with the UA80 8 speech automatic transmissions. Toyota is aware of this issue but only a few vehicles have been recalled. It is thought to be a problem with manufacturing.

NHTSA ID

11748643

Incident

Jun 8, 2026

Vehicle started making a high pitched noise when accelerating at around 98,000mi. I took the vehicle in for the 100,000mi service at 100,854mi and had them also look at this issue. I was told that there was a failure in the front carrier pinion shafts and they recommended replacing the transaxle assembly and rear main seal for $8,354. The vehicle was certified with a 100,000mi power train warranty, but it was just out of warranty. I discovered that there is a class action lawsuit against Toyota for knowingly installing transmissions in 2017 to present vehicles that were known to fail prematurely.

NHTSA ID

11746836

Incident

Jun 26, 2026

My 2021 Toyota Highlander is experiencing the documented transmission issue impacting vehicles with the UA80E transmission. Our transmission whines and experiences a hesitation or jerks the vehicle. Especially under acceleration. My vehicle was purchased brand new from Toyota. Serviced at a Toyota dealership since purchase.

NHTSA ID

11746426

Incident

Jun 24, 2026

Transmission started to whine and act erratically during driving. These effects put safety of those in the vehicle at risk by causing distractions to whomever was driving the vehicle, taking their focus off driving. The vehicle was taken to the dealer who confirmed the transmission needed to be replaced due to an internal failure. They said they were able to quickly diagnose this problem because "they saw it a lot." There were no warning lamps or messages from the vehicle.

NHTSA ID

11746320

Incident

Jun 17, 2026

The transmission is in the whining stage of transmission failure. It has been confirmed by Cumberland Toyota in Cookeville, TN. There were no warning lamps, etc. however Toyota did post a Technical Service Bulletin (TSB) on February 09, 2021 that my vehicle would have transmission issues. My warranty expired the last of April 2026 and I am over the mileage warranty by 800 miles. I recognized the whining on June 21, 2026 and reported to Toyota on June 22, 2026. Toyota knew this transmission was going to fail and most are being reported just outside the 60,000 mile warranty. I have asked for help and assistance from the local dealership as well as corporate, but both have declined to assist.

NHTSA ID

11746240

Incident

Jun 21, 2026

Transmission needed! 76,000 miles and Toyota will not address the issue! We have owned Toyotas for 30 some years! Sienna, Avalon, RAV4, Sequoia, and now the Highlander!!!!! There is a massive issue with the transmission across the board in the 2021 and 2022 Highlander and Toyota will not replace.

NHTSA ID

11746003

Incident

Jun 6, 2026

After just passing 100K miles, there is now a whirling noise upon acceleration. After taking to an auto repair shop, they narrowed it down to the transmission and said it was a known problem (referenced T-SB-0008-21) and suggested I take it to the dealership. I took to the dealership where a service manager offered to ride with me to confirm and he confirmed the issue was in fact the known problem noted from the technical service bulletin. The Toyota dealership assistant service manager stated that the noise (which he said was coming from a final drive gear bearing) would continue to get progressively worse and that despite being a known issue, there was no remediation available aside from replacing the transmission completely. He said that he saw no reason that I could not continue to drive the car without complications and without the transmission going completely out for at least a couple more years, but that the noise would get progressively louder until you could no longer tolerate the noise level and would need a new transmission at that point (despite it just beginning last week (or my just noticing it), you can hear it over the the radio when at a low to moderate volume). If this is a "known issue," (ie: a defect that is only in some of the cars per the T-SB-0008-21 notice) this does not seem like a reasonable answer to 'just wait until you can't stand the noise level with acceleration and then completely replace your transmission as there is nothing we can do for you' but it was suggested that I could take it to a body shop that would rebuild transmissions and they may could replace that part.

NHTSA ID

11745875

Incident

Jun 16, 2026

I own a 2021 Toyota Highlander with approximately 127k miles. The vehicle has developed a noticeable whining/whirring noise during acceleration. The noise appears to originate from the drivetrain/transmission area and has become increasingly noticeable over time. The condition occurs every-time during acceleration and is present under normal driving conditions. I am concerned that this may indicate a transmission or drivetrain-related issue that could affect vehicle reliability and safety. I have found reports from other 2021 Toyota Highlander owners describing similar symptoms involving whining noises during acceleration. The vehicle has been inspected by a Toyota dealership. And is certified through Toyota. The vehicles was bought new from the Toyota dealership and has had all service done through Toyota. I am submitting this complaint so NHTSA can evaluate whether this condition is part of a broader pattern affecting similar vehicles as a defect in the original transmission built in the SUV.

NHTSA ID

11745579

Incident

Jun 11, 2026

I own a 2021 Toyota Highlander with approximately 93,000 miles. The vehicle developed transmission symptoms including whining noise. A Toyota dealer diagnosed internal transmission failure and recommended complete transmission replacement at a cost of approximately $9786.31. Toyota declined repair assistance. I am concerned because a transmission failure at this mileage is unexpected and appears similar to other owner complaints involving the 2021 Toyota Highlander transmission.

NHTSA ID

11745289

Incident

Jun 15, 2026

The transmission in my 2021 Toyota Highlander began producing a whining noise during acceleration between approximately 15-50 mph at around 80,000 miles. The noise stops when the accelerator is released and has progressively become louder. The vehicle was inspected by a Toyota dealership. I was informed that the condition is a known issue affecting some Toyota vehicles, but no repair was offered because the vehicle is outside the 5-year/60,000-mile powertrain warranty. There are currently no warning lights or diagnostic trouble codes. I am concerned that the transmission may fail while driving, resulting in loss of power or propulsion and creating a safety risk for myself and other motorists. The vehicle remains available for inspection.

NHTSA ID

11744884

Incident

Jun 16, 2026

Transmission makes a metallic whining sound when you accelerate. Associated and confirmed to be transmission failure. Vehicle has 65,000 miles on it and failure is considered premature. The specific transmission, UA80, is known to have manufacturing defects that cause this problem

NHTSA ID

11744703

Incident

Jun 15, 2026

The vehicle transmission has a distinct whine noise as previous models have had. This is a known issue with these transmissions.

NHTSA ID

11744339

Incident

Jun 14, 2026