general problems of the 2021 Toyota Highlander - part 1

197 problems related to power train have been reported for the 2021 Toyota Highlander. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2021 Toyota Highlander based on all problems reported for the 2021 Highlander.

1 Power Train problem

Failure Date: 07/28/2026

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.

2 Power Train problem

Failure Date: 07/23/2026

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.

3 Power Train problem

Failure Date: 07/16/2026

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.

4 Power Train problem

Failure Date: 07/13/2026

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).

5 Power Train problem

Failure Date: 06/29/2026

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.

6 Power Train problem

Failure Date: 06/26/2026

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.

7 Power Train problem

Failure Date: 06/24/2026

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.

8 Power Train problem

Failure Date: 06/23/2026

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.

9 Power Train problem

Failure Date: 06/22/2026

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.

10 Power Train problem

Failure Date: 06/21/2026

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.

11 Power Train problem

Failure Date: 06/17/2026

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.

12 Power Train problem

Failure Date: 06/16/2026

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.

13 Power Train problem

Failure Date: 06/16/2026

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," (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.

14 Power Train problem

Failure Date: 06/15/2026

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.

15 Power Train problem

Failure Date: 06/15/2026

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.

16 Power Train problem

Failure Date: 06/14/2026

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

17 Power Train problem

Failure Date: 06/13/2026

Right after the manufacture warranty of 60k miles, the car began to make a humming noise. I took the car into the dealership with 65k miles on 13 Jun 2026, and the Toyota dealership stated that the humming is caused by the transmission and we will need to replace the entire transmission. The cost would be $9,447. 29. This issue is known by Toyota and Toyota put out Toyota service bulletin (t-sb-008-21) but failed to issue recall for this defective transmission.

18 Power Train problem

Failure Date: 06/13/2026

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!.

19 Power Train problem

Failure Date: 06/11/2026

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.

20 Power Train problem

Failure Date: 06/08/2026

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.

21 Power Train problem

Failure Date: 06/06/2026

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.

22 Power Train problem

Failure Date: 06/05/2026

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.

23 Power Train problem

Failure Date: 05/30/2026

We purchased our 2021 Highlander xle in the spring of 2024. It came with a powertrain warranty up to 60,000 miles. Unfortunately for us, we're at 65,000 miles and recently started hearing a high-pitched, whining noise when we accelerate. We took it to the Toyota dealership and they told us we need the transmission replaced. A new transmission is around $9,000, before taxes and service fees. We haven't had any other issues and haven't had an accident. There's already a class-action lawsuit against Toyota regarding their Highlander models having ua80 transmission issues. Because of this, we called corporate in hopes they will pay for it under their goodwill assistance program. However, because we never had the Highlander serviced at a Toyota dealership before, they told us they won't cover anything. We've routinely serviced this vehicle. We happened to purchase it at a Nissan dealership, so getting maintenance at Toyota didn't cross our minds. Regardless of where we got the car serviced, it's obvious there's a recurring problem with the Highlander's transmission that Toyota has refused to acknowledge, which is costing consumers around $9,000 apiece. We feel cheated by Toyota, and we hope they eventually have to make things right.

24 Power Train problem

Failure Date: 05/21/2026

My 2021 Toyota Highlander was making a high pitched whine sound upon acceleration with the sound level holding steady at a consistent speed. We took the vehicle to a Toyota dealership to have it looked at and were told the transmission needs to be replaced. No other warnings were received. We are concerned about our safety if the transmission goes out while on the road.

25 Power Train problem

Failure Date: 05/19/2026

My 2021 Toyota Highlander makes a whining sound when driving. Took vehicle to dealership and was told it is a $10,000 repair and repair is critical.

26 Power Train problem

Failure Date: 05/17/2026

My car start with a noise and just lost power in the middle of the road causing almost an accident. This was caused due to the manufacture issue for the transmissions with my car model and brand.

27 Power Train problem

Failure Date: 05/15/2026

2021 Highlander began with whining noise around may 15, 2026 and just outside the warranty. Had the vehicle inspected at the Toyota dealer for repair. They informed me the transmission failed and needs replaced for a price of $9600. Found on the internet that many folks are having the same transmission issue on several Toyotas made in 2021 with a ua80e or ua80f transmission. Toyota issued a technical service bulletin (t-sb-0008-21) on February 9, 2021! we received no warning until the whining noise. We attempted a “goodwill case” to get Toyota to help pay but were denied for the simple reason we used our own mechanic. This has absolutely no effect on this transmission failure. Since Toyota was always aware of this issue I feel they should be held accountable. This is a major faulty product.

28 Power Train problem

Failure Date: 05/04/2026

I own a 2021 Toyota Highlander with approximately 100,500 miles. The vehicle has developed a noticeable whining noise coming from the transmission/drivetrain area that continues to worsen over time. The noise is most noticeable during acceleration and while driving at highway speeds. I brought the vehicle to Toyota for inspection and was informed that the issue is related to the transmission. However, Toyota denied repair assistance because the vehicle is outside the powertrain warranty period. After researching the issue, I discovered multiple similar complaints involving 2021 Toyota Highlanders equipped with the ua80 transmission, including Toyota technical service bulletin t-sb-0008-21 regarding “whine or grind noise from the transmission. ” the symptoms described in the bulletin closely match the symptoms my vehicle is experiencing. Toyota appears aware of this transmission-related issue, yet many owners outside the warranty period are being denied coverage despite similar failures and complaints. I am concerned this may represent a broader transmission defect that could lead to premature transmission failure, unsafe driving conditions, hesitation, loss of power, or expensive repairs for consumers. I believe this issue should be investigated further by NHTSA due to the growing number of similar complaints involving whining transmission noises and transmission failures in Toyota Highlander vehicles. At this time, the vehicle has not yet experienced a complete transmission failure, but the condition is worsening and raises significant concerns regarding reliability and safety.

29 Power Train problem

Failure Date: 05/01/2026

Transmission. My 2021 Toyota Highlander with approximately 94,500 miles developed a consistent whining noise during acceleration. The issue occurs daily during normal driving and appears to be worsening. A Toyota dealership diagnosed the problem and confirmed the noise is coming from the transmission and that the transmission requires replacement. This appears to be a premature failure of a major drivetrain component. The condition could lead to loss of power or transmission failure while driving, creating a potential safety risk. There was no prior warning, and the vehicle has been properly maintained.

30 Power Train problem

Failure Date: 05/01/2026

The transmission on the 2021 Toyota Highlander failed at only 5 1/2 years old (66,000 miles). This is a known issue from Toyota and they should be held responsible to cover items just barely out of warranty for well maintained vehicles.

31 Power Train problem

Failure Date: 04/26/2026

Car makes a high pitched whining noise at low speeds of approx. 10-30 mph.

32 Power Train problem

Failure Date: 04/24/2026

2021 Toyota highalnder ua80f transmission whine / known defect - potential for sudden failure I own a 2021 Toyota Highlander platinum v6 awd (ua80f 8-speed automatic transmisstion) purchased in July 2021. Current milage is 78k. Starting 3 days ago I noticed a faint whine noise coming from the transmission. The pitch changes with speed and when the throttle is depressed (it's louder under load/acceleration). This matches the exact symptoms described in Toyota TSB t-sb-0008-21 for whine/grind noise caused by the front carrier assembly pinion shaft issues in 2021 Highlanders with ua80 transmissions. On April 27, I went to a Toyota dealer to confirm the source of the noise and diagnose. As per their diagnosis report "tech took vehicle on road test to duplicate concern, after confirming complaint vehicle was then lifted up and inspected while under a load, tech as able to isolate noise to transmission at this time, fluid level and condition was inspected to ensure there were no signs of shavings or discoloration and after inspection tech found nothing abnormal during fluid level check. Tech then ran a health check to ensure there were no dtc present related to transmission concern and found no dtc present. Recommend replacing transmission and torque converter at this time". They provided a quote of $9,392. This condition represents a safety concern because the internal wear can progress to harsher shifting, loss of power, limp mode, or complete transmission failure while driving, potentially causing a crash or stranding the vehicle in traffic. I have audio/vehicle recordings of the whine and service records showing regular Toyota dealer maintenance. I am requesting the the NHTSA investigate this ongoing ua80 transmission issue as it appears to be a known manufacturing or design defect tat continues beyond the narrow TSB applicability and warranty limits.

33 Power Train problem

Failure Date: 04/17/2026

My automatic transmission failed per the dealership and is just outside of the warranty but is considered a premature failure based on the expected life of the vehicle.

34 Power Train problem

Failure Date: 04/15/2026

My 2021 Toyota Highlander equipped with the ua80 transmission developed a whining/grinding noise under acceleration around 73,000 miles. Toyota diagnosed internal transmission failure and recommended full replacement costing approximately $9,000. Toyota issued TSB t-sb-0008-21 acknowledging defects involving the front carrier assembly pinion shafts in these transmissions. This defect creates a potential safety hazard due to possible loss of power or drivability during highway operation. I am requesting that NHTSA investigate the widespread transmission failures affecting 2021 Highlanders and related Toyota vehicles.

35 Power Train problem

Failure Date: 04/07/2026

A whining noise was observed at around 78k miles. Brought to the dealer and they indicated parts in the transmission are failing and it requires replacement. They said this has been happening more frequently on 2021 Highlanders (also see t-sb-0008-21). It's also a well-documented issue online. My contact with Toyota was that they did not intend to cover any repairs as the vehicle is out of warranty, even though it's not an isolated issue. They would not disclose how many vehicles have reported this issue. I believe it has reached safety recall-level.


Other Power Train related problems of the 2021 Toyota Highlander

Power Train problems
198
Automatic Transmission problems
2

Highlander Service Bulletins
Highlander Safety Recalls
Highlander Defect Investigations