Toyota UA80 Transmission Lawsuit: Symptoms, Repair Costs, Cases

The Toyota UA80 transmission lawsuit refers to at least three pending class actions in federal court alleging that the eight-speed automatic transmission in more than a million Toyota and Lexus vehicles sold since 2017 suffers from hardware and software defects that cause harsh shifting, shuddering, sudden power loss, and premature failure. The suits accuse Toyota of knowing about the problems since before the transmission ever reached customers and continuing to sell affected vehicles without a recall or permanent fix.¹

Which Vehicles Are Covered

The UA80, marketed by Toyota as the “Direct Shift-8AT,” is installed across a wide slice of the lineup. The lawsuits, taken together, cover:

Toyota Highlander, 2017–present
Toyota RAV4, 2019–present
Toyota Grand Highlander, 2023–present
Toyota Camry, 2017–2024
Toyota Sienna, 2017–2020
Toyota Avalon, 2019–2022
Lexus ES 350, 2019–present
Lexus ES 250, 2021–present
Lexus RX 350, 2023–present
Lexus NX 250 and NX 350, 2022–present
Lexus TX 350, 2024–present

Because the Highlander and RAV4 are among Toyota’s top sellers, the litigation potentially reaches over a million vehicles on the road.²³

Symptoms Owners Are Reporting

Owner complaints across the affected models describe a consistent pattern. The most common symptoms include shuddering or vibration between roughly 25 and 50 mph under light acceleration, delayed response when pressing the accelerator from a stop, unexpected gear slipping at highway speeds, and sudden jerking at low speeds during shifts.⁴ Some drivers report whining or clunking noises during acceleration and deceleration, and in the worst cases, a complete loss of power mid-drive.¹

Plaintiffs allege that when they brought these problems to authorized Toyota and Lexus dealers, they were often told nothing was wrong, that the behavior was “normal” for the eight-speed, or that no permanent repair was available.⁵

What the Lawsuits Say Is Defective

The complaints describe two connected problems. On the hardware side, one identified flaw involves the counter drive gear sub-assembly: a retention nut secured by a locking tab that plaintiffs say was not bent sufficiently at the factory, allowing the nut to loosen over time. When it does, the bearing shifts and the transfer gear produces whining, clunking, harsh shifting, and eventually a reduced-power mode.⁶⁷⁸

The software allegation is separate but related. According to the complaints, the transmission, engine, and powertrain control modules are calibrated to push early upshifts and keep the torque converter clutch engaged as much as possible in order to maximize fuel economy figures. Plaintiffs argue this constant cycling generates heat, stresses internal components, and degrades the torque converter clutch material, and specialists have reported UA80 fluid turning nearly black from clutch debris well before the fluid smells burnt.⁶

The suits also allege Toyota knew about all of this before the transmission reached customers. The LeBoutheller complaint places Toyota’s awareness “since at least August 2016” based on presale durability testing, and the Murphy complaint alleges knowledge from design failure mode analysis, customer service hotline logs, and dealer reports.⁵

Has Toyota Issued a Recall

No. Despite consumer complaints to NHTSA going back to 2017 and Toyota’s own service bulletins acknowledging specific failures, the automaker has not issued a recall covering the UA80, and available reporting does not indicate that NHTSA has opened a formal investigation.⁴

Toyota has taken narrower steps. In 2019, it published Customer Support Program POL19-04, which covers the loose retention nut issue in certain 2017–2018 Sienna and Highlander vehicles for up to 10 years from the vehicle’s first use date regardless of mileage, and reimburses owners who already paid out of pocket.⁹ The 2021 TSB addressed the pinion shaft defect in select 2021 Highlander, Avalon, and Camry models. Neither measure covers the full range of vehicles or failure modes the lawsuits allege.

Repair Costs and Warranty

For owners whose transmissions have already failed, dealer quotes for a full UA80 replacement run roughly $7,300 to $13,000, based on owner reports compiled by automotive media.⁸ The official repair for the pinion shaft defect is replacement of the entire transaxle, which Toyota estimates at seven to nine hours of labor.⁷

Toyota’s standard powertrain warranty covers the transmission for five years or 60,000 miles. The lawsuits call this warranty “unconscionable,” arguing Toyota knew failures would often surface right around or just past the warranty limit. Some owners have received “goodwill adjustments” covering 50 to 100 percent of parts and labor, but the coverage is inconsistent, and many owners are told simply that their vehicle is out of warranty and no recall exists.⁸

The Cases and Where They Stand

Three federal class actions are active. None has been certified, and none has reached settlement.

Murphy v. Toyota Motor Sales

Filed in the U.S. District Court for the Central District of California (2:20-cv-5892), with the first amended complaint filed December 15, 2020. It focuses on 2017-and-later Highlanders and Siennas and centers on improper calibration between the powertrain control module and the valve body. The plaintiffs are represented by Capstone Law APC.⁵

Natale v. Toyota Motor Corporation

Filed November 4, 2025, in the U.S. District Court for the Eastern District of New York (2:25-cv-06150) before Judge Joan M. Azrack. The 350-page complaint names eleven plaintiffs and, unlike the earlier case, sues Aisin Corporation and Aisin World Corp. of America alongside Toyota, reflecting the joint development of the transmission. Claims are brought under the Magnuson-Moss Warranty Act. The defendants received an extension until July 31, 2026, to respond.¹⁰

LeBoutheller v. Toyota Motor Sales

Filed in December 2025 in the U.S. District Court for the Eastern District of Texas (4:25-cv-01389). This is the broadest of the three cases, covering both Toyota and Lexus models from the 2017 model year to the present. LeBoutheller has demanded a jury trial and seeks damages, restitution, injunctive relief, and an order requiring Toyota to repair, recall, or replace the defective transmissions.⁴

What Owners Can Do Now

If you own one of the affected vehicles and are seeing the symptoms, document them. Keep dealer repair orders, diagnostic printouts, and any correspondence with Toyota corporate, including denials, goodwill offers, or statements that the behavior is “normal.” Owners of 2017–2018 Siennas and Highlanders should check whether their vehicle falls under Customer Support Program POL19-04, which reimburses prior out-of-pocket repairs for the retention nut failure.⁹ Filing a complaint with NHTSA adds to the record the lawsuits rely on. Because the class actions have not been certified, no claim form exists yet; owners who want to participate in a class if one is certified generally do not need to opt in, but preserving records now is what makes a later claim usable.

1
ClassAction.org. Toyota, Lexus UA80 Transmission, Torque Converter Problems Caused by Defects, Class Action Lawsuit Says
2
NJ Law Journal. 1 Million Vehicles: Class Action Focuses on Toyota Transmissions
3
Autoblog. Toyota Transmission Lawsuit New Jersey
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Top Class Actions. Class Action Alleges Toyota Sold Vehicles With Defective UA80 Transmissions
5
ClassAction.org. Murphy v. Toyota Motor Sales USA Complaint
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GEARS Magazine. The Toyota UA80: Worth Another Look
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NHTSA. Toyota TSB T-SB-0008-21
8
Torque News. Toyota Highlander Transmission Failure: Explaining the $8,000 Repair Affecting 2020-2024 Models
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NHTSA. Toyota Customer Support Program POL19-04
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PACER Monitor. Natale et al v. Toyota Motor Corporation et al