Toyota Avalon gen 5 2019–2022 Transmission: Common Issues and Expert Verdict
Overview
The 2019–2022 Toyota Avalon sits on the TNGA-K platform. Front-wheel drive only. No transfer case, no PTU, no rear diff, no driveshaft to worry about. Simple layout. I like simple.
You’ve got two completely different transmission personalities depending on what’s under the hood. The 3.5L 2GR-FKS V6 gets the UA80E 8-speed automatic. The hybrid runs the P710 eCVT tied into the A25A-FXS 2.5L system. Same car. Very different hardware inside.
I’ve worked on both. They don’t fail the same way. They don’t age the same way. And they definitely don’t cost the same when things go sideways.
There are no U.S. transmission recalls hanging over this generation. That matters. But there are Toyota service bulletins that tell a story — calibration changes, internal carrier noise, sealing concerns. You read between the lines long enough, patterns show up.
Which Transmissions It Uses
UA80E
- Model code: UA80E
- Gear count: 8-speed
- Drive layout: FWD
- Engine pairing: 3.5L 2GR-FKS V6
- Production years: 2019–2022
- No verified alternative transmissions used in V6 models
This is a compact transverse 8-speed with aggressive lock-up programming. Designed for fuel economy. Tight tolerances. Thin fluid. Not an old-school slushbox.
P710
- Model code: P710
- Gear type: eCVT planetary power-split
- Drive layout: FWD
- Engine pairing: 2.5L A25A-FXS Hybrid
- Production years: 2019–2022
- No verified alternative transmissions used in hybrid models
This isn’t a belt CVT. No push belt. No stepped clutches. It’s a planetary set tied to electric motors. Mechanically simpler than the 8-speed in some ways, over-engineered in others.
No AWD versions. No manual options. What you see is what you get.
Main Failure Patterns
UA80E – Flex Lock-Up Calibration (TSB T-SB-0122-20)
This one showed up early. Mostly 2019 V6 cars.
Customers came in complaining about weird engagement, occasional MIL lights. Scan tool shows P07407E or P27567F. Torque converter clutch logic. Pressure control. That sort of thing.
Toyota released T-SB-0122-20. ECM reflash. Software fix. No hard parts replaced in most cases.
In my experience, when the update was done early, the Tranny lived a normal life. When it wasn’t? I’ve seen clutch material in the pan earlier than I’d like. Nothing catastrophic, but accelerated wear. A calibration problem that, left alone, can turn into a mechanical problem. That’s how it goes.
UA80E – Whine or Grind (TSB T-SB-0008-21)
This one’s more serious. 2021 builds. Serial-number-specific.
Customer says there’s a whine under throttle. Maybe a faint grind. Not loud enough to scare you at first. Then it gets worse.
Toyota identified an internal front carrier assembly issue involving pinion shaft components. The fix in T-SB-0008-21? Replace the whole unit. No partial repair. No band-aid fix. Full transmission swap.
I’ve seen a few of these. Not dozens. Not epidemic. But when they fail, they fail internally. And once you hear that carrier noise, that’s not something you ignore. That’s metal moving where it shouldn’t.
UA80E – Side Cover Leak (T-TT-0580-19)
2019–2020 cars mostly.
Fluid seepage at the side cover. No impact damage. No cracked case. Just weeping.
Toyota’s internal technical tip basically said: contact Technical Assistance before you dive in. That tells you they were watching it.
Now here’s the real issue. These transmissions don’t like being low on fluid. They run warm by design. You start dropping fluid level, operating temps creep north of 230°F (110°C), oxidation speeds up, and the clutch packs start wearing faster than they should. Slow damage. Quiet damage.
I’ve torn down units that ran low for months. You see darkened fluid, fine shavings, glazing on friction material. Not grenaded. Just tired early.
UA80E – Shift Feel Complaints
Some people think the Tranny is failing when it isn’t.
This 8-speed uses aggressive torque converter lock-up even at low speeds. That’s for fuel economy numbers. It can feel abrupt. Hesitation off the line. A slightly firm 1–2 shift once warm. Adaptive learning that feels inconsistent.
I’ve driven brand-new ones that felt that way. No codes. No damage. Just calibration strategy.
You need to separate feel from failure. A lot of owners don’t.
P710 Hybrid Transaxle
The hybrid unit is a different animal.
No stepped gears. No traditional clutch packs engaging 1 through 8. It’s a planetary power-split device with motor-generators doing most of the work.
I’ve seen these well past 150,000 Miles (241,000 km) without internal mechanical failure. That’s field observation, not marketing fluff. They just don’t chew themselves up the way multi-gear automatics can.
When problems happen in hybrids, it’s usually electronics, inverter cooling, or something upstream. The mechanical core of the P710 is solid. Boring, even. And boring is good.
Typical Repair Costs
Let’s talk money. Because this is where reality hits.
| Repair Type | Parts (USD) | Labor (USD) | Total (USD) | Mileage Context |
| ECM Reprogram (TSB T-SB-0122-20) | $0–$150 | $120–$250 | $120–$400 | Usually under 60,000 Miles (96,000 km) |
| UA80E Transmission Replacement | $4,500–$6,000 | $1,000–$1,800 | $5,500–$7,800 | Out of warranty |
| Side Cover Leak Repair | $100–$300 | $400–$900 | $500–$1,200 | 30,000–100,000 Miles (48,000–160,000 km) |
| Axle Seal Replacement | $50–$150 | $300–$600 | $350–$750 | Any mileage |
| P710 Hybrid Transaxle Replacement | $3,500–$5,500 | $1,000–$1,800 | $4,500–$7,300 | High mileage, uncommon |
Those are service bay benchmark numbers in the U.S. Dealer pricing can go higher. Independent shops sometimes shave a bit off with reman units. Either way, a full UA80E replacement north of $6,000 USD will ruin your week.
Drain and refill? Under 4 Quarts (3.8 Liters) typically. Cheap insurance compared to a replacement. Toyota doesn’t scream about aggressive fluid intervals for normal use. I’ve seen enough dark fluid at 70,000 Miles (113,000 km) in city-driven cars to ignore that idea.
Best and Worst Years
| Year | Powertrain | Transmission | Dominant Concern | Relative Risk |
| 2019 | 3.5L V6 | UA80E | Lock-up calibration update cases | Moderate |
| 2020 | 3.5L V6 | UA80E | Isolated side cover leak reports | Low–Moderate |
| 2021 | 3.5L V6 | UA80E | Serial-range internal carrier noise | Moderate (build-specific) |
| 2022 | 3.5L V6 | UA80E | No major documented transmission bulletins | Low |
| 2019–2022 | Hybrid | P710 | No recurring mechanical defect pattern | Low |
If I’m buying used, I’m more concerned about build date and service records than the badge on the trunk. A late-build 2019 that got its software update is better than an early one that didn’t.
Warning Signs & Early Detection
- Delayed engagement into Drive
- Whine that rises with RPM
- Grinding under moderate load
- Red fluid around the case seam
- Torque converter-related DTCs stored
When I inspect one of these pre-purchase, I don’t just drive around the block. I get it to full operating temp, around 180–200°F (82–93°C). Then I test low-speed modulation. Parking lot maneuvers. Gentle throttle. Then moderate acceleration.
I scan for pending codes. Check calibration ID. Look at fluid color and smell. Burnt fluid is a warning sign. Dark brown in a supposedly “lifetime” unit tells you everything you need to know.
Fluid analysis past 70,000 Miles (113,000 km) is smart if you’re keeping the car long term. Cheap compared to a teardown.
When to Walk Away
Here’s where I get blunt.
- Confirmed internal carrier noise and no warranty coverage
- Repeated pressure-control codes after reflash
- Visible metal shavings in drained fluid
- Harsh flare combined with burnt smell
A $7,000 USD transmission replacement on a midsize sedan kills resale math fast. If the Tranny is already lunching itself, you don’t negotiate your way out of that.
Ownership Reality
Manufacturers publish guidance. Real life does something else.
| Topic | OEM Position | What I See in the Shop | Cost Impact |
| Fluid Service Interval | No aggressive interval under normal use | Fluid darkens by 60,000–80,000 Miles (96,000–129,000 km) in urban driving | Ignoring it shortens clutch life |
| Software Updates | Applied when symptoms appear | Many cars never updated unless owner complains | Uncorrected calibration can accelerate wear |
| Warranty Coverage | 5 years / 60,000 Miles (96,000 km) powertrain | Some failures show up just outside that window | $5,500–$7,800 repair exposure |
| Hybrid Transmission Maintenance | No stepped clutches to service | Fluid still oxidizes over time | Preventive drain and refill lowers long-term risk |
I’ve watched owners trust the “lifetime fluid” idea across multiple brands. It’s optimistic. Heat is real. Friction is real. Fluid breaks down. That doesn’t make this transmission bad. It makes physics undefeated.
Lawsuits, Complaints & Regulatory History
No major class-action lawsuits targeting the UA80E or P710 in this generation.
Documented Toyota publications include:
- T-SB-0122-20 – ECM logic update for lock-up and pressure codes (2019 V6)
- T-SB-0008-21 – Internal transmission noise, serial-range-specific (2021 V6)
- T-TT-0580-19 – Side cover leak guidance (2019–2020)
NHTSA complaints cluster around hesitation and shift feel on early 2019 V6 cars. Enough to notice. Not enough to trigger a recall. No AWD means no rear driveline recall exposure either.
VIN lookup at a dealer is the only way to confirm whether a specific car falls into a serial range addressed by a bulletin. Guessing doesn’t work here.
Bottom Line
This isn’t a ticking time bomb platform. It’s also not indestructible.
The P710 hybrid transaxle is boring in the best way. Low failure rate. Minimal drama. I’ve seen high-mileage examples that just keep going.
The UA80E 8-speed in V6 cars is generally solid, with three watch areas: early calibration logic, side cover seepage, and a serial-range internal carrier issue. Most cars will never see catastrophic failure. The few that do, it’s expensive.
Maintenance, software status, and build range matter more than odometer reading alone.
Treat the fluid like it isn’t magic. Listen for noise. Scan for codes. Do that, and this generation of Avalon can be a very uneventful ownership experience. And uneventful, in the transmission world, is exactly what you want.
