2021 Acura Tlx

The transfer case and transmission splines have been stripped causing the car to be FWD only. The issue was confirmed by the dealer, and both the transfer case and transmission were replaced under warranty. The car shuddered, followed by a drivetrain noise for a few seconds. No warning lights or messages appeared when the incident occurred. The issue occurred at approximately 26,574 miles on the odometer.

transfer case leaking fluids at 73,000 miles

Transmission and transfer case failure. Noticed a very small amount of fluid leaking and took to dealership. Dealer informed me that I was "lucky" to have noticed and that the transfer case spline failure had occurred. Notified that the problem could lead to sudden loss of all wheel drive and loss of vehicle control, vehicle slipping, and oversteer. DP26001 had indicated that these issues are a safety concern and could lead to an accident. I had noticed instability in certain issues where the rear of the car did not feel firmly planted when cornering (oversteer). Dealer indicated that both the transmission and transfer case need to be replaced. I was ~8000 miles within powertrain warranty. Parts are on a national backorder which indicates a widespread issue. No warning lamps or indication of seal failure that leads to stripped splines off the shaft due to the fluid leak. NHTSA does not understand how the Acura SH-AWD system interacts with vehicle dynamics and handling, and loss of the rear wheel drive and its impact on oversteer would be absolutely NO DIFFERENT than a rear sway bar breaking under load while cornering. I experienced this exact symptom on [XXX] where the road goes from 3 lanes to 2 lanes on a sweeping right hand curve. This is where I had felt like I may lose control of the vehicle, the rear of the car started to come around and I had to steer into the slide to regain control of the vehicle. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I'm losing power than normal all of a sudden. When I step on the gas after light hits green in sport and sport plus mode my car losses traction even when traction control is on, and I hear a loud clunck sound. After the the loud clunck sound the car losses RPM while driving I step off the gas and step back on it and the RPM goes back to normal again.

I took this vehicle to get serviced in the summer of 2025. I recently joined an Acura Type S (2021+) group on Facebook and learned that the issue is quite prevalent. I had to have the transmission and transfer case replaced due to transmission issues and traction issues

On July 7th 2026 I was driving home, came to a stop light at normal speed, when the light turned green I took off at normal speed and I heard a huge cluck / bang from underneath the car and it bogged and didn’t want to move. I then stepped on the gas because of the Car behind me getting to close and my traction control light started to flash and the car started to shake and feel very uncomfortable to drive . After that I realize only the two front wheels of the car were working and even at low cruising speeds the car feels very unsafe and shakes and hear noises I never heard before the part that is causing this is the transfer case and transmission thus there are many other people who have had this same issues ranging from 21 to 23 tlx type s with 15k miles to 100k miles

Transmission splines went out and transfer case has also failed which is only sending power to front wheels

On 07/01/2026, at approximately 8:00 AM, during steady acceleration, flashing of MIL with loss of power presented northbound after merging from 235 west bound to I-135 north bound near Park City, KS. Particularly dangerous resulting in near rear end collision. Upon taking nearest exit ramp, attached BlueDriver .OBD II reader, and fault code P0303 - Cylinder 3 Misfire and U0401-68 PGM-Fi/ECM/PCM system event code was logged, with multiple warning indicators that safety system, AWD, brake, and other systems were disabled. Note, vehicle has had TSB 20-053 update w/ flash of PGM-Fi which did not resolve the fault, fault associated with hot and humid climates or period of rain fall, apparent water vapor, condensate build up in intercooler. For Honda Accord and Acura RDX w/ 4 cylinder 2.0 TDGI engine TSB includes redesigned intercooler replacement, that is not available for TLX 21-25 which is currently out of production. This has occurred previously during humid and hot weather, but no intermittent flashing MIL does not store code. Thankful in this instance P0303 and U0401-68 code is stored, and scheduling service at dealership to diagnose misfire.

2021 Acura TLX Type S SH-AWD. Total mechanical failure of PTU/transfer case spline interface at 29,800 miles within factory powertrain warranty. Vehicle operated silently in FWD-only with no warning lights, no fault codes, and no dashboard alerts — consistent with all complaints cited in NHTSA Defect Petition DP26001 (opened March 6, 2026, NHTSA #11712885). Failure confirmed by dealer via lift test: propeller shaft and rear wheels stationary while fronts spun. During actuator test, Check AWD System light illuminated for the first time — because the lift removed road-induced wheel rotation that had masked the failure from the ECU throughout normal driving. This is the only condition under which this failure mode is electronically detectable. Dealer replaced transmission (remanufactured ATR kit) and PTU under warranty. Repair took 38 days. CRITICAL-THIRD PTU REVISION: Replacement PTU installed was part #29000-5YK-070. Known revision history: -050 (original, confirmed failure part) → 060 (revised ~2022) → 070 (installed June 2026). The 070 does not appear in any public OEM parts database. Acura has now revised this component three times with zero TSBs, zero public disclosure of engineering changes, and no recall. The 070 revision appearing after DP26001 opened in March 2026 suggests a silent root cause fix while avoiding formal recall obligations. CRITICAL-DPSM GOODWILL CLAUSE: Acura required acceptance of "One Time Goodwill Authorized by DPSM" as condition of repair. This was a warranty obligation, not a goodwill gesture. This clause was imposed while DP26001 is under active federal review, before factory warranty expires, with no confirmed root cause fix. If the 070 part fails again, this clause may be used to deny future warranty coverage. Requesting: (1) complaint added to DP26001 record; (2) Acura compelled to disclose engineering changes between part numbers 050, 060, 070; (3) investigation of DPSM Goodwill clause as systematic pre-recall liability limiation

I am submitting this complaint in reference to NHTSA Defect Petition DP26001, opened March 6, 2026, investigating loss of all-wheel drive capability in 2021-2023 Acura TLX vehicles due to interfacing spline failure between the transmission and the power takeoff unit (transfer case). I am the owner of a 2021 Acura TLX SH-AWD with 55,300 miles. I purchased this vehicle on June 2nd, 2026. I have not yet experienced a failure, but I am registering as an affected vehicle owner given the known defect pattern documented in DP26001 and consistent with the 137,329-vehicle population identified in the NHTSA investigation. The failure mode as described in DP26001 involves stripping of splines at the transmission-to-PTU junction, resulting in sudden and complete loss of rear-wheel drive without warning lights or dashboard indication. Documented repair costs for this failure range from $5,000 to $19,000 depending on extent of damage. I am registering this complaint to be included in the documented owner population should the petition escalate to a formal defect investigation or recall. I request notification of any recall action, extended warranty coverage determination, or technical service bulletin issued for this failure pattern.

El problema es exactamente en el tanque de la gasolina, se está saliendo la gasolina en la unión de la manguera de llenado con el tanque de gasolina. Esto representa un riesgo no solo para mi seguridad sino también para cualquier persona.

While accelerating from a stop, I heard a loud bang from the drivetrain area and initially believed another vehicle had struck the rear of my car. After checking my surroundings, I realized there had been no collision. Immediately after the incident, the vehicle lost power delivery to the rear wheels. The vehicle is designed as an all-wheel-drive performance sedan, and the sudden loss of rear-wheel power significantly changed the way the vehicle handled. The vehicle became effectively front-wheel drive without warning, causing all engine power to be directed through the front wheels. This resulted in reduced traction, altered handling characteristics, and increased front tire wear. No warning lights, messages, or indicators appeared on the dashboard before or at the time of the failure. There were no symptoms that alerted me that a drivetrain failure was about to occur. The vehicle was inspected by an Acura dealership, and Acura confirmed failure of the transfer case and transmission components associated with the all-wheel-drive system. The transfer case and transmission are currently being replaced under the manufacturer's drivetrain warranty. I believe this failure created a safety risk because the vehicle unexpectedly lost its intended all-wheel-drive capability while in operation. Drivers rely on the handling, traction, and stability characteristics of the SH-AWD system. The sudden and unannounced loss of rear-wheel power changed the vehicle's behavior and could increase the risk of loss of control, particularly during acceleration, cornering, emergency maneuvers, or operation in poor weather conditions. The failed components are available for inspection through Acura as part of the warranty repair process.

Transfer case failure. I was driving my 2021 Acura TLX Type S when I suddenly heard a loud pop from underneath the car. Right after that, the SH AWD system stopped working and the car was only driving in front wheel drive. There were no warning lights or signs before it happened, due to it being a mechanical failure and not an electrical one because the car does not have sensors for the transfer case. After getting it checked out, I was told the splines between the transfer case and transmission were stripped. I’ve also seen that a lot of other 2021 to 2023 TLX Type S owners have had the same problem. It’s concerning because the AWD system failed out of nowhere, especially since the car depends on it for traction and stability. The car now needs a new transfer case and possibly more drivetrain repairs. (Proof shown in pdf down below, only front wheels spinning)

I drive a 2021 Acura TLX 2.0 L turbo 4 cylinder. I was driving to work on [XXX] on a busy street in Boyle Heights, Ca. When all of sudden I get a warning indicator “engine temp is high do not drive”. Pulled over immediately. Good thing I was in the far right lane and was able to pull over and not stall or get rear ended by another vehicle behind me. There were no warning, symptoms and indicators of the engine's overheating. My vehicle has been in great condition prior with no major or minor issues with my vehicle. We took it to two dealerships for diagnostics. The head gasket blown, empty coolant reservoir, cracked engine block, and other parts of the engine were affected. What if I was on a highway and the car stalled. I could’ve been seriously injured or seriously injured someone else on the road. Acura corporate is aware of our situation and refuse to own their engine safety defects. They want us to pay out of pocket to repair our vehicle. My car is 5 years old there is no way out of nowhere my vehicle should have this type of engine issues. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Dealers are investigating and need replacing rear shocks/solenoids, stroke sensors, and wiring harnesses. The issue is commonly identified as corrosion in the rear stroke sensor wiring harness or faulty damper make "Adaptive Damper System" (ADS) error light on and can't not make change for the setting as acura design issue !

Took my car for an oil change and found that the transfer case is leaking its fluid. Known to lead to tranfer case failure.

} I am submitting an update to my previous complaint. In my original complaint, I stated that the vehicle had not received transmission service. After reviewing my records, I confirmed that a transmission fluid service (drain and refill with inspection) was performed at an Acura dealership in July 2024. Despite this maintenance, the transmission still failed at approximately 84,000 miles. I am providing this update to ensure the complaint is accurate

I am reporting a transmission failure in my 2021 Acura TLX with approximately 84,300miles. While driving under normal conditions, after about 30 minutes on the road, I came to a stop at a red light. When I attempted to accelerate again, the vehicle would not shift out of first gear. The engine would rev, but the transmission failed to upshift. I also experienced a hard and abrupt engagement when shifting the vehicle into reverse. This issue occurred suddenly without warning and made the vehicle unsafe to operate in traffic, as I was unable to accelerate properly or maintain normal driving speed. The vehicle has been regularly serviced at an Acura dealership. At the time of the incident, the transmission fluid had not yet been replaced but had recently been recommended during a scheduled service visit. The vehicle is currently at an Acura dealership where I normally get the car serviced. The dealership has diagnosed the issue as an internal transmission failure and is recommending a transmission replacement.

Sunroof exploded during drive on highway. No contact was made by any small or large objects

The awd transfer case failed and require replacement along with the transmission