2018 Toyota Highlander

While driving my 2018 Toyota Highlander (UA80F transmission), I began noticing a faint high-pitched whining noise between 25–45 mph around 63,000 miles. Over time, it progressively worsened, eventually including intermittent jerking and hard low-speed shifts, particularly during acceleration or uphill climbs. In wet conditions, the drivetrain lurches slightly under throttle, increasing risk of loss of control. I had a transmission fluid drain and fill service performed by a Toyota dealership at ~58,000 miles, along with full 4WD maintenance (differentials and transfer case). Despite this, symptoms developed shortly afterward. Toyota was notified and a corporate case was opened. I provided clear sound recordings, videos, and a full inspection history, and cited their Customer Support Program ZJC (POL19-04) for known defects related to UA80F whine and washer tab failures. Although my build date falls within the general failure range, Toyota refused coverage and claimed it was “operating to spec.” Tier 1 support initially confirmed ZJC eligibility, but Tier 2 reversed course with no follow-up. Dealership service also failed to elevate the case properly to my Zurich warranty provider, who required dealer confirmation to proceed. Multiple other owners have reported similar failures around 60K–100K miles, and I believe this is a dangerous latent defect that Toyota is attempting to narrowly contain. Whining precedes jerking, and jerking precedes full failure. Many complainants, like me, are met with stall tactics, deflection, or no follow-through. There were no warning lights or diagnostic codes, but the safety risk is growing. I believe this transmission issue deserves expanded CSP eligibility and potential recall investigation.

The contact owns a 2018 Toyota Highlander. The contact stated that while driving at various speeds and attempting to accelerate, the transmission whined abnormally loud. No warning light was illuminated. The vehicle was taken to a local dealer to be diagnosed. The contact was informed that the transmission needed to be replaced due to internal failures. The vehicle was not repaired because the warranty had expired. The manufacturer was notified of the failure by the local dealer. The failure mileage was approximately 107,000.

I brought my car to the dealership due to a small whining noise when accelerating over 30mph. Technician determined the noise is coming from internal transmission failure and recommended replacement. The small whining noise was the only indication something was wrong. No check engine or warning lights on my dashboard. The car is under 50,000 miles at the time.

The 2018 Toyota Highlander has less than 100K miles on it and has been diagnosed with an $11K repair for essentially a new engine! The dealership (Coughlin Toyota, Heath OH) has said it needs cylinder head assembly for $10,684.20. The error message we are getting is a "Check Engine" light "Take Vehicle to Dealership" and the AWD/ Traction Control shuts off. When searching online forums, there are MANY people experiencing the same problem, apparently a well know issue with Toyota (not just Highlanders). We have only owned this vehicle for a few years and believe this is a manufacturer error that desperately needs investigated. Please.

My 2018 Highlander Transmission (8 speed model UA80) began a whine noise characteristic of Customer Support Bulletin POL19-04 when the vehicle hit 101k miles. Toyota performed an inspection on 8/9/2024 and recommends full transmission + transfer case replacement. The dealer confirmed also confirmed the issue is characteristic of POL19-04, but because the vehicle was manufactured 6-months after vehicles bracketed in POL19-04 (based on the transmission serial number) it is not included in the support program therefore not covered. Toyota UA80 transmissions have continued to have this issue (example - T-SB-0008-21 for '21 UA80 transmission). While Toyota acknowledges replacement of transmission is necessary to maintain a safe drivetrain, no customer-facing error messages are evident. Also note - transmission fluid has been maintained only using Toyota's recommended Fluid (Toyota branded WS ATF) at Toyota's specified intervals.