2021 Toyota Highlander, 65K In, Needs a New Transmission - The Owner Adds, “We Purchased a Toyota New From the Dealer For Its Reliability, and to Have This Happen is Unacceptable”

Toyota's "bulletproof" reputation just took a $10,000 hit, and this owner isn't staying quiet.

Imagine this: you spend your hard-earned savings on a brand-new Toyota Highlander SUV, specifically choosing the one brand synonymous with "bulletproof" reliability to ensure your family's safety for the next decade. Then, at just 65,000 miles, barely broken in by traditional standards, the dealer hands you a $10,000 repair estimate and tells you that because you are slightly past the warranty, you are completely on your own.

Heather Haynes Pentico on the Toyota Highlander Owners Club Facebook page says,

“I am apparently not the only member of the 2021 Toyota Highlander group that is having transmission issues. I took my Highlander in for an oil change and mentioned that it has started making a humming noise when accelerating. They suggested that we call the dealer, as it’s likely the transmission. The dealer checked it out and basically said, “You're screwed, and I need a new transmission, and we can't help you. (because it's out of warranty). So, we invested in a new Toyota from the dealer, and for it to have only 65,000 miles is unacceptable. Toyota is supposed to be reliable. Has anyone else had this transmission situation, and do I have any possible recourse from Toyota?”

The 2021 Toyota Highlander Transmission Nightmare

As a Senior Reporter at Torque News with over 30 years in the automotive industry, I have seen brands rise and fall on the strength of their powertrains. I have spent decades under hoods and behind the wheels of every generation of Toyota’s midsize SUV. Usually, when I write about a Highlander, it is to praise its longevity. But lately, the 2021 model year has become a focal point for a troubling trend: premature 8-speed transmission failure.

When a loyal owner like Heather Pentico invests in a Toyota, she isn't just buying a car; she is buying a promise of "worry-free" ownership. To have that promise shattered at 65,000 miles is more than just a mechanical failure; it is a breach of brand trust.

The "Humming" of Impending Doom

The issue usually starts subtly. Many owners report a faint humming or whining noise during acceleration, often between 15 and 60 mph. This isn't a "normal" road noise; it is often the sound of the pinion shafts in the front carrier assembly failing. Toyota is well aware of the issue. In February 2021, the company released Technical Service Bulletin T-SB-0008-21, acknowledging that some 2020-2021 Highlanders might exhibit this exact noise.

The fix? A complete transmission replacement.

This brings me to a critical point I’ve discussed before regarding the evolution of this model. While newer Toyotas push the envelope on technology, sometimes the older, simpler designs were more robust. I recently wrote about this contrast in my report: Today Was the Day, 301K Miles On My 2008 Toyota Highlander, But Letting This Family Member Go Is Sad, I Just Hope This New 2026 Highlander Performs As Well. In that story, we see the high bar Toyota set for itself, a bar that the 2021 model is currently struggling to clear.

The 5-Year/60,000-Mile Warranty Trap

The most heartbreaking part of Heather’s story is the timing. Toyota’s powertrain warranty expires at 60,000 miles. For those who hit the failure mark at 65,000 or 70,000 miles, the dealer's response is often a cold, "You’re out of luck."

From my experience, I can tell you that a transmission failing 5,000 miles after a warranty ends is a prime candidate for what we call "Goodwill Assistance." Dealerships have a certain amount of latitude to advocate for their customers with Toyota Corporate, especially when a TSB exists. If your dealer says they can't help, they are often choosing not to go to bat for you.

Why the 2021 Gas Model Is Different From the Hybrid

It is vital to distinguish which Highlanders are facing this "unacceptable" fate. The 2021 Highlander gas models use the Direct Shift 8-speed automatic (UA80E/F). This is the unit involved in the whining and grinding complaints. Conversely, the Hybrid models use an eCVT, a completely different mechanical animal that has remained remarkably reliable.

I’ve spent a lot of time analyzing these differences to help buyers make the right choice. If you are considering a used Highlander, you need to know which powertrain to trust. You can find my detailed breakdown on this in: We Bought a 2023 Toyota Highlander When They First Came Out, I Hated the Engine and Got Rid of It, Now the Dealer Wants a Deposit To Test Drive the Hybrid. While that story focuses on the 2023 turbo vs. hybrid, the lesson is the same: the hybrid system is often the safer bet for long-term reliability.

What Should Highlander Owners Do?

If you find yourself in Heather's shoes, do not simply accept an $11,000 bill. Here is my professional roadmap for fighting back:

Reference the TSB: Bring a copy of T-SB-0008-21 to your service advisor. Show them that Toyota has documented this as a known manufacturing defect, not "normal wear and tear."

Request a "Goodwill Repair": Ask for the Service Manager, not just the advisor. Use the phrase "Goodwill Assistance" and emphasize your brand loyalty.

Contact Toyota Brand Engagement: If the dealer won't budge, call Toyota's corporate customer service (1-800-331-4331). Open a case and explain that a known defect occurred just past the warranty period.

File a Report with the NHTSA: Document your failure on the National Highway Traffic Safety Administration website. If enough owners report this, it could trigger a formal recall.

We know these SUVs can be lifesavers. I've covered stories in which the Highlander's structural integrity was the only thing standing between a family and tragedy. You can read about that incredible safety record here: “This 2018 Toyota Highlander Saved My Life Today”: Mom And Daughter Walk Away After 55 MPH T-Bone By Sleeping Truck Driver. It is because the Highlander is such a fantastic vehicle in every other category that this transmission issue feels like such a betrayal.

Key Takeaways for Highlander Owners

• Listen for the Whine: If your 2020-2022 gas Highlander starts humming on acceleration, get it documented by a dealer immediately; ideally, before 60,000 miles.
• Maintenance Matters: While the TSB suggests a mechanical defect, my recommendation for longevity is to perform regular transmission fluid "drain and fills" (not flushes) every 60,000 miles.
• The Hybrid Advantage: If you are shopping for a used Highlander, the Hybrid version avoids the 8-speed transmission issues altogether.
• Persistence Pays: Many owners on Reddit and Facebook have successfully had their transmissions replaced for free or at a "split cost" after being persistent with Toyota Corporate.

What Highlander Owners Are Saying

The sentiment across the web is shifting from "Toyota for life" to "Never again." Here is what the community is reporting:

User "Mlang-2000" on Reddit: "If it's the trans and outside the powertrain warranty, it's $10k, and Toyota isn't helping anyone. There are a couple of class action lawsuits that will take years." 

User "Adventurous_Wing8554" on Reddit: "I have just found out I need a new transmission in my 2021 Highlander, 73,000 miles. Toyota knew about this problem but sent it through to dealers. Their negligence has shown they don't care what they roll off the line." 

User "eatdrinkdrink" on Reddit: "Got a quote for 12K (in CA) to replace my transmission... with the whining sound upon acceleration as the only sign of a problem."

Wrapping It Up

The 2021 Toyota Highlander remains a leader in safety and family utility, but the growing number of transmission failures at low mileage is a stain on its reputation. For a brand built on the "Quality, Durability, and Reliability" (QDR) pillar, letting loyal customers foot a five-figure bill for a known manufacturing defect is, as Heather put it, simply unacceptable. Toyota needs to do more than issue bulletins; they need to stand behind their product with extended warranties for this specific component.

How About You?

Have you noticed a strange humming or whining noise coming from your 2020-2022 Toyota Highlander, or have you already faced a massive repair bill? Share your experience in the comments below; your story could help other owners get the "goodwill" assistance they deserve.

Next Up: Think your Highlander is the only Toyota facing "known" issues? A 2025 owner is finding out that even the brand-new models have carry-over problems from years ago. Read more here: 2025 Highlander Owner's Roof Is Leaking First Time In the Rain, She Adds, “I've Heard Toyota's Known About This Issue Since 2020, You'd Think They'd Have Fixed It By Now”

With over 30 years of industry experience, Denis Flierl brings an insider’s perspective to Torque News, where he has been a Senior Reporter since 2012. Before picking up the pen, Denis consulted for the automotive industry's biggest brands and honed his skills as a test driver. He cuts through the noise to deliver the latest auto news, compelling owner stories, and the expert analysis necessary to navigate today's changing automotive market.

Have a tip or question? Follow me on X @DenisFlierl and @WorldsCoolestRides, or connect with me on Facebook, Instagram, and LinkedIn.

Photo credit: Denis Flierl