2021 Toyota Highlander

My vehicle is experiencing a transmission safety issue that has been diagnosed by the authorized Toyota dealer service center (Toyota of Scranton). During my most recent service visit on 3/2/26, the dealer reported that the transmission is “failing and whining” and recommended full transmission replacement. This condition creates unsafe driving behavior, including abnormal whining noise during acceleration and the concern for sudden transmission failure while driving. The Highlander started exhibiting issues with the transmission within the past 7 days. This issue appears consistent with the known transmission defect referenced in Toyota Technical Service Bulletin T‑SB‑0008‑21, which addresses whining and grinding noises caused by internal transmission component failure in 2021 model‑year vehicles equipped with UA80-series transmissions. Multiple independent reports indicate that this condition can worsen and may lead to loss of power or drivability while the vehicle is in motion. For safety reasons, I am submitting this complaint so the issue can be evaluated as part of any ongoing or future defect investigations. I am concerned about the potential risk of transmission failure while driving, which could increase the chance of a crash.

The contact owns a 2021 Toyota Highlander. The contact stated that while driving at an undisclosed speed, there was a whining sound coming from the vehicle. There was no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed with transmission failure. The dealer stated that the transmission needed to be replaced. The vehicle was repaired. After the vehicle was parked and turned off, there was transmission fluid leaking from the vehicle. There was no warning light illuminated. The vehicle was taken back to the dealer, where it was diagnosed and determined that the head gasket had failed and needed to be replaced. The vehicle was repaired. The contact then noticed fluid leaking from the transfer case while the vehicle was parked and turned off. The vehicle was taken back to the dealer, where it was diagnosed and determined that the transfer case had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 74,700.

At around 70,000 mi the transmission started making noises and at the 80,000 mile marker I took it in for its maintenance they found debris in the transmission fluid and I was just told it's either a replace it now or replace it when it falls out of the vehicle. A vehicle with less than 100,000 mi and I am the only owner, for the transmission to go out or start going out and Toyota not solve problems is ridiculous

The contact owns a 2021 Toyota Highlander. The contact stated that while driving at an undisclosed speed, there was an abnormal whining sound coming from the transmission. The contact was concerned about the sound and contacted a dealer. The vehicle was driven to the dealer and was diagnosed with transmission failure. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 60,347.

I am reaching out regarding our 2021 Toyota Highlander which currently has $65 K miles and is just out of warranty. Recently we noticed a wining noise during acceleration. We took the vehicle to the dealer who told us that the transmission will need to be REPLACED. $9500 repair. This is a known issue with Toyota and they will not work with us on this. We are stuck! No customer goodwill! Thank you!