general problems of the 2021 Acura TLX - part 1

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

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.

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).

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

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 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.

} 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.

2021 Acura Tlx a-spec sh-awd and my transmission is leaking from the seal between the transmission and the differential. Acura is not sure if they can cover it under warranty because I am slightly past the powertrain warranty even though they had my car about a week ago when it was just barely past that point and no one said anything about the leak on the transmission until I checked with a certified Acura mechanic somewhere else. This is not just some small problem because with fluid leaking and leaving it will eventually damage the transmission and the differential or even just make them completely give out. This can be gears grinding and overheating. It is not just a problem it is also a safety hazard if this starts dripping onto the exhaust pipe or even on the road behind making traction a problem for someone behind. This needs to be under a recall not just warranty with how much I see this happening to these cars this is ridiculous we have to go through this.

My vehicle was performing as expected, but there was a smell of burning oil or rubber. When I took the car into the dealership the found that the transmission was slipping and the transfer box was failing. In the video they sent of the initial inspection there is obvious brown sludge leaking from the transmission. I was told that a complete transmission and transfer case was required.

Driving towards the gas station, still at lows speeds while I was in the neighborhood so speed limit was 15mph. I can hear and feel the car struggle to move forward, about 2 minutes into the drive a hear a big toon and check engine light is on for about a minute before going away. I filled gas and headed back home and I heard a larger toon but this time all the warning light came up. These are all errors reported by the car at the same time - vehicle stability system - hill start assist problem - addictive cruise control system problem - collision mitigation braking system problem - road departure mitigation system problem - emission system problem - all wheel drive system problem - brake system problem these are all errors that appeared on the Acura app - emission system problem - vehicle stability system - electric parking brake problem - electric power steering problem - adaptive cruise control problem.

I am submitting this complaint regarding a sudden and premature transfer case failure on my 2021 Acura Tlx type s equipped with Acura’s super handling all-wheel drive (sh-awd) system. The failure occurred during normal driving conditions and without prior warning indicators. Based on my experience and numerous similar reports from other owners of this vehicle, this appears to be an ongoing and systemic issue that warrants formal investigation and recall consideration. While accelerating under normal road conditions, I heard a loud and distinct “pop” noise from underneath the vehicle. The sound was abrupt and mechanical in nature, as if an internal drivetrain component had failed. Immediately following the noise, the vehicle’s driving characteristics changed noticeably. Although the car continued to move forward and there were no immediate warning lights illuminated on the dashboard, the drivetrain behavior was clearly altered. After the incident, the vehicle began operating as though the majority of drivetrain load was being directed to the front wheels. The vehicle now feels significantly front-heavy during acceleration and general driving. There is a distinct change in weight transfer and torque delivery that was not present prior to the failure. The balance that is characteristic of a rear-biased sh-awd performance system is no longer present. There were no grinding sounds, fluid leaks, or vibration at the time of failure. There were also no warning messages, check engine lights, awd system warnings, or drivetrain alerts displayed to notify me of any malfunction. The failure occurred suddenly and without notice. I respectfully request that NHTSA open a formal investigation into premature transfer case failures on 2021–2023 Acura Tlx type s vehicles equipped with sh-awd. This issue should be evaluated for recall eligibility or mandated corrective action to ensure driver safety. Thank you for reviewing this complaint.

The transfer case in my Acura Tlx type s failed due to the internal splines stripping at approximately 57,600 miles. I heard a loud bang while attempting to maneuver out of a parking spot that was covered in snow. When this occurred, the transfer case was no longer able to transfer power to the rear wheels, causing the all-wheel-drive system to stop functioning. As a result, the vehicle effectively operated as front-wheel drive only. The most concerning part of this failure is that the vehicle provided no warning whatsoever to the driver. There were no dashboard alerts, drivetrain warnings, awd system warnings, or check engine lights indicating that the awd system had failed. The vehicle continued to operate and display information as if everything was functioning normally. This occurred during the winter in new york while driving in snowy conditions, where the awd system is critical for traction and safety. Because there was no warning that the awd system had failed, I continued driving the vehicle assuming it still had awd capability. On multiple occasions the vehicle became stuck in snow due to the loss of rear-wheel power. A critical drivetrain component such as a transfer case should not fail under normal driving conditions at this mileage. Additionally, a vehicle equipped with awd should provide a clear warning to the driver if the system is no longer functioning. The absence of any warning combined with a sudden loss of awd capability creates a serious safety concern, particularly in winter climates where drivers rely on awd for traction and control. Under the wrong circumstances this type of failure could potentially lead to an accident or serious injury.

This 2021 Acura Tlx type-s has experienced a complete failure of the transfer case after approximately 40,000 miles of use. This unfortunately is a known issue on the online forums for this vehicle in model years 2021-2023. I have a video inspection performed by the local dealership proving this. The only warning is a one-time loud boom when accelerating and a leaking from the transfer case of fluid thereafter. There is no safety issue best I can tell, however the car only performs in front drive mode once the transfer case quits working. The issue is due to weak splines within the transfer case that shear off and thus damage the 10-speed automatic transmission in the process. Acura has a 6 year 70,000 mile warranty, so a complete replacement is covered, however my concern is for whether the new transfer case part # 29000-5yk-060 which replaces the old 29000-5yk-050 part will do the same. This is a very expensive fix into the 5 figures (over $10,000) and really needs to have a recall as there are dozens and dozens of owners online who have experienced this failure.

Short description transmission-to-ptu splines, causing awd loss and requiring full transfer case and transmission replacement. Summary this drivetrain failure poses an unreasonable safety risk due to the sudden loss of awd capability, lack of alerts, and resulting instability. My experience is consistent with dozens of documented cases and matches the mechanical fault pattern already under federal review. Given the potential for severe loss of vehicle control, a full investigation and corrective action (including a recall) is necessary. Symptoms sudden awd loss loud bang or grinding only front wheels receiving power no warning lights safety risks loss of directional stability wheel spin under acceleration hazard in inclement weather cost & extent of repairs many cases require complete drivetrain replacement costing $13k–$19k. Prevalence 137k+ vehicles, NHTSA dp26?001 currently open.

Transfer case needs replacing.

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

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.

Was driving the car under normal acceleration when the transfer case failed. No power to the rear wheels. Acura dealer confirmed the problem. Will be fixed under warranty. No warning lamps or messages on the dash.

Transfer case blew. Awd was not working.

- the transfer case failed causing the awd system to stop working -it is a safety concern because you may lose control since no power is going to rear wheels, especially in inclement weather that we receive in the northeast. -yes the problem has been confirmed by dealership by putting car on lift and seeing that no power is being sent to the rear wheels. -there are no warning lights or any signs, you just hear a loud bang while driving and lost of traction while accelerating.

Transfer case has gone out. No longer getting power to the rear wheels as it is a awd car. Problem has not been checked by the dealer yet. There were no warning lights on the dashboard when it went out.

While performing a right turn, under normal acceleration a loud "pop/clunk" occurred. I immediately pulled into a parking lot as the vehicle was still able to drive. The vehicle runs as normal, no leaks of any kind present. Nothing visibly broken. Afterwards, I was able to determine with the vehicle suspended off of the ground, I am getting power only to the front wheels. Utilizing google, it's easy to see that this has become a massive issue on this particular model Tlx type s. The vehicle will be taken to Acura on Monday Aug 18th 2025 for diagnostics, but it's quite obvious that the splines on the transfercase at the transmission mounting location have sheared completely, thus making the vehicle front wheel drive powered only. Given my current situation, my hope is that Acura will honor the power train warranty as it is my understanding that both the transmission and the transfercase are required to be replaced in this instance. Acura also needs to issue an updated transmission/ transfercase combination and a recall because this is happening way to often and it's quite an expensive repair.

While driving my 2021 Acura Tlx type s, I began losing traction frequently during normal daily driving, especially when turning corners or accelerating from a stop sign or stop light. At first, I believed the issue was related to my tires, so I replaced them, but the same problem continued. After researching online, I discovered that transfer case failures are a known issue on these vehicles, affecting both new and used models. Currently, my vehicle is at the dealership, but they were unaware of this recurring transfer case problem and have no information about it. This is concerning because the failure of the transfer case directly affects traction and stability, creating a potential safety risk to myself and others on the road. It appears to be a systemic issue that Honda/Acura has not yet acknowledged.

The all wheel drive failed do to transfer case splines being sheered off between the transmission and transfer case. No warning lights are on to warn of the rear wheel tires not receiving power to them. I was not aware of this problem and this could have contributed to and accident, as I though the awd was working, but it wasn't.

The all wheel drive (awd) system of the vehicle became partially inoperable after hearing a loud bang under normal vehicle acceleration some time in early 2025. The vehicle did not trigger or display any warnings stored in the onboard computer or on the dash display that the awd system had any faults or issues. Had this system failed during an emergency situation involving hazardous or dangerous driving conditions like snow, ice, heavy rain, it could have caused me to not have improved capable vehicle handling. The vehicle's ability to distribute power evenly to all 4 wheels was hindered and operating as front wheel drive only after the loud noise was observed. Additionally, transmission gear oil began leaking underneath the vehicle around the transmission casing. The issue has been reproduced, confirmed, and validated by technicians of a local Acura dealership. The dealership was approved to completely replace the following two components of the awd system under the manufacturer's 6 year / 60k mileage powertrain warranty: 1. Transmission 2. Transfer case - also known as power transfer unit or ptu.

My car has suffered a well known issue in the 21-25 Acura Tlx community. At 71,000 miles my transfer case splines stripped also with the transmission splines. Resulting in me having to pay out of pocket to replace both the transmission and transfer case. I’m really hoping Acura does a recall for this issue. I really like this car and don’t want to have to replace them again. Like I mentioned before. I’m in a facebook Tlx group and people are constantly posting about theirs blowing.

Transfer case broken; no longer sending power to the rear wheels. Car loses traction when accelerating from a stop.

Awd system is no longer working. Every time I accelerate the front wheels are slipping and there are no warning lights or system failure messages. I believe this is a transfer case issue as there are now videos on youtube about Tlx type s's having this issue.

-transmission and transfer case failed, specifically the splines on the input shaft connecting the two, rendering the vehicle fwd instead of awd. Parts are not available to inspect as they were returned to dealer. -while the vehicle could still function in front wheel drive, the lack of awd could be a safety risk in poor weather or road conditions, especially given that the vehicle does not send an error code for this issue. -problem was reproduced by the dealer, who replaced both parts after a 2-month wait for parts. -there is zero indication that these components failed, no error codes or anything. The car also displays how much power is going to each wheel on the gauge cluster, and displays just as it did when everything worked. The problem can only be noticed when using awd, so many drivers may not know they have this issue. I experienced the traction control light blinking on hard acceleration due to front tire slip and understeer during turns, but beyond that there was no indication anything was wrong. -the dealer informed me this would be a $12,000 repair out of warranty, which I find unacceptable given that the car doesn't give any error codes. Many many people may not know their car is effected.

• transfer case failure, leading to transmission damage. • vehicle gives no indication of transfer case failure, in turn, giving the driver the impression that the vehicle is awd. Potential risk to safety as the failure happened under normal driving conditions, vehicle suddenly jolts, with loss of power. • problem addressed by dealership service dept. But not able to recreate, as this is a drivetrain fault. • vehicle and components inspected by dealership service dept. Only. • no indications or warning lights for tc failure. Awd system on dashboard indicates power is going to all four wheels when this is not the case.

Transfer case failure. Spline is stripped after 40k. Awd is disabled. Requires new transfer case and transmission.

While driving normal, I heard a pop sound coming from the bottom of the car which resulted in my awd not working. On acceleration the car would spin the front wheels and the traction light would light up. Took to dealer and they confirmed the transfer case and transmission failed and had to be replaced. The splines between both components had stripped.

Transfer case failure with no warnings or symptoms of problem prior to failure. This is a safety issue as my car was only operating in front wheel drive due to the transfer case failure. This is a common issue that needs to be investigated.

The all-wheel-drive stops working and the car becomes front wheel drive only. There are no warning lights on. The only way you could tell is to jack the car up with all four wheels off the ground and put it in drive to see if all four wheels are spinning. Also the driveshaft should be turning out of the transfer case. The the roads are wet or with snow the front wheels brake free very easy and the traction light comes on, which is also sign. I took it to the dealer and they verified the issue. They said it needs a new transmission and transfer case because the splines on the output shift of the transmission strip out and also damage the splines on input shaft of the transfer case.