2016 Tesla Model S transmission problems

Filed Sep 29, 2026 · Transmission · TX

I am requesting help with a very common issue on Tesla Model S and X vehicles that they refuse to extend warranty to repair. The rear drive motor on all performance models made from 2012-2020 have a very common issue of a faulty internal factory seal that should prevent liquid coolant from entering the electric rear drive motor and destroying it. I received 1 warning before my car shut off and stranded me at a storage facility where I had to spend the night in my hot car because the facilities gates shut and lock at 11pm and reopen at 6am. I had no way to get out of the facility and I didn’t want to abandon my car with windows down and unlocked. I stayed with my vehicle until the wrecker service got there at noon the next day to transport my vehicle to the local Tesla service center. After the technician performed his inspection he notified me that the rear drive until had been ruined due to the faulty seal failing. The only option I was offered was a replacement rear drive motor for $7400. I am not in the position to just fork over that much money. I had to purchase a inexpensive car to travel to work daily. I honestly believe that Tesla knows the design and manufacturing process is flawed and that all rear drive motors will eventually fail due to this factory defect. The company should stand behind the products they make after being aware of this very important manufacturing defect. This occurred 8-25/26-2026 with 81,092 miles. If you review any Tesla forum, you will see that this is a serious issue that is dangerous and unsafe for consumers. I don’t feel like it should be the consumer’s responsibility if this is a known issue with these particular years and models of the vehicles they build. Please review this matter and help me and many other consumers with a defective product that is dangerous, inconvenient, and extremely costly for customers.

Filed May 4, 2026 · Acceleration, Electrical · CA

I own a 2016 Model S P100D equipped with the Large Drive Unit (LDU). The component that fails is the rotor coolant seal in the rear drive unit motor. Coolant leaks internally into the motor and inverter, causing bearing wear, corrosion, isolation faults, and eventual complete drive unit failure. The affected drive units are still installed and available for inspection upon request. This defect puts my safety and the safety of others at risk because it can cause sudden loss of propulsion (especially at highway speeds), power reduction, or total drivetrain shutdown, potentially leading to a crash. Coolant in high-voltage areas also raises electrical fault/fire risks. The problem is widely reproduced and confirmed: Tesla service centers are familiar with it and replace failed units with updated “-U” revisions that include a coolant bypass. Independent EV shops confirm the exact root cause (rotor seal failure) via encoder inspections showing coolant intrusion and through disassembly. This is a documented pattern failure in all 2012–2020 LDU vehicles. No police or insurance inspections have occurred yet, as no crash or total failure has happened. Tesla is aware of the recurring issue through service records on similar vehicles. Early symptoms before full failure typically include rear motor whining/grinding (especially under load), reduced power warnings, “Rear Drive Unit Fault” messages, and visible coolant on the speed sensor. These can appear gradually. My vehicles have not yet experienced total failure, but the defect is known to be inevitable. I am proactively monitoring encoder sensors. Because this is a systemic design defect affecting thousands of vehicles with clear safety implications, I request the federal safety agency open an investigation and require Tesla to issue a recall for free repairs/replacements on all affected 2012–2020 LDU vehicles.

Filed May 4, 2026 · Acceleration, Electrical · CA

I own three 2016 Tesla vehicles with the same known safety defect: two Model S P100D and one Model X P100D, all equipped with the Large Drive Unit (LDU). The component that fails is the rotor coolant seal in the rear drive unit motor. Coolant leaks internally into the motor and inverter, causing bearing wear, corrosion, isolation faults, and eventual complete drive unit failure. The affected drive units are still installed and available for inspection upon request. This defect puts my safety and the safety of others at risk because it can cause sudden loss of propulsion (especially at highway speeds), power reduction, or total drivetrain shutdown, potentially leading to a crash. Coolant in high-voltage areas also raises electrical fault/FIRE risks. The problem is widely reproduced and confirmed: Tesla service centers are familiar with it and replace failed units with updated “-U” revisions that include a coolant bypass. Independent EV shops confirm the exact root cause (rotor seal failure) via encoder inspections showing coolant intrusion and through disassembly. This is a documented pattern failure in all 2012–2020 LDU vehicles. No police or insurance inspections have occurred yet, as no crash or total failure has happened. Tesla is aware of the recurring issue through service records on similar vehicles. Early symptoms before full failure typically include rear motor whining/grinding (especially under load), reduced power warnings, “Rear Drive Unit Fault” messages, and visible coolant on the speed sensor. These can appear gradually. My vehicles have not yet experienced total failure, but the defect is known to be inevitable. I am proactively monitoring encoder sensors. Because this is a systemic design defect affecting thousands of vehicles with clear safety implications, I request the federal safety agency open an investigation and require Tesla to issue a recall for free repairs/replacements on all affected 2012–2020 LDU vehicles.

Filed Apr 17, 2026 · Electrical, Transmission · FL

The rear Large Drive Unit (LDU) has coolant intrusion due to a known design defect in the internal rotor seal. Coolant from the stator cooling system is leaking past the seal into the motor, degrading the winding insulation. An independent inspection by The Electrified Garage (Orlando, FL) on 04/08/2026 confirmed moisture at the rotor sensor (yellow condition) and degraded insulation resistance measured at 3.0 megohms (should be hundreds of megohms on a healthy unit). The vehicle requires a complete drive unit replacement at an estimated cost of $7,000. This is a well-documented design defect affecting 2012-2016 Model S vehicles. Tesla has acknowledged the issue by redesigning the seals in later production units and performing "coolant deletes" on remanufactured replacement units, but has not issued a recall or extended warranty coverage. The vehicle currently has 53,542 miles and no prior drivetrain warnings, yet the drive unit is failing due to a manufacturing/design defect, not owner abuse or normal wear.

Filed Feb 24, 2026 · Fuel system, Transmission · AZ

While driving in traffic, the vehicle displayed warnings stating “Unable to drive — Pull over safely.” The vehicle progressively lost power and became unable to propel itself, requiring me to stop in traffic. Additional warnings indicated reduced acceleration and performance. The vehicle remained powered (screens and electronics active) but could no longer drive. Tesla later diagnosed a high-voltage battery failure and provided an estimate for full battery replacement. The sudden loss of propulsion in traffic created a safety hazard because the vehicle could not accelerate or continue moving with traffic.

Filed Feb 11, 2026 · Transmission · MO

I am reporting a safety-related defect involving sudden loss of motive power on my 2016 Tesla Model S. During the drivetrain warranty period, the vehicle developed a persistent humming/buzzing noise from the rear drive unit. This noise was documented on video with a timestamp confirming it occurred while the vehicle was under warranty. At the time, there was no loss of performance or warning indicators. Due to the distance to the nearest Tesla service center (approximately 200 miles), the vehicle was not immediately inspected. When I later contacted Tesla Service, the vehicle was approximately three weeks outside the drivetrain warranty. Upon inspection, Tesla advised that the rear drive unit was failing and would require replacement at customer expense. Tesla declined warranty coverage despite evidence that the failure symptoms began during the warranty period. The rear drive unit later catastrophically failed while the vehicle was being driven uphill, resulting in a complete loss of propulsion. Prior to this incident, Tesla service personnel had advised that if the rear motor failed, the front motor would allow the vehicle to operate in a limp mode to reach a safe location. This did not occur. When the failure happened, the vehicle lost all motive power and was unable to maintain position on an incline. The vehicle nearly rolled backward into traffic. Police assistance was required (911 call) to redirect traffic so the vehicle could be rolled backward down the hill to a safe location. A minor child was present in the vehicle at the time. I am aware that failures of rear drive units on 2016–2017 Tesla Model S vehicles related to coolant intrusion have been reported by Tesla service personnel and other owners. This incident demonstrates a serious safety risk involving sudden loss of power and incorrect guidance regarding vehicle behavior during drive unit failure. I believe this represents a safety-related defect warranting investigation.

Filed Jun 8, 2025 · Transmission · CA

I wanted to bring a situation to your attention, report an incident and understand why model years 2012-2020 Tesla Model Ss have not been recalled for a defective drive unit. This is a known defect - known by Tesla. There have been no recalls for mine - VIN number [XXX] . On [XXX], my 2016 Tesla Model S suddenly lunged and jerked down to less than 5 mph from about 45 mph in 5-10 seconds as a result of a defective and failed drive unit, here in San Ramon , CA. NO WARNING. We forced the car to lunge and hop over to the median with traffic stopping, building up, honking, braking....truly a miracle no one got hurt. I later saw both front and back wheels turning in OPPOSITE directions, simultaneously, as the tow truck driver was pulling the car on his flat bed. The tow truck driver said he has never seen anything like this! The defective drive unit has been a known issue which they corrected in 2020. A Master Tesla mechanic states that this is not about IF the failure was to take place, but WHEN it was going to take place. Tesla refuses to own up to the problem despite emailing their Head, Tom Zhu. I came across this conversation on Reddit and it appears that a comment made by the Tesla mechanic below is relevant. They could have prevented this by recalling the cars and changing the coolant seal. Here is his quote: "Every single large Tesla Drive unit will fail unless it's a recent revision U replacement (~2022 or newer) or has been retrofitted by a 3rd party. This applies to all RWD Model S made between 2012 and 2020, and all Performance S/X made until 2020. The coolant seal will fail and destroy the motor. This is not an if, but a when. If you have a car with one of these motors, there are a variety of 3rd party shops who can fix this issue forever for a lot less money than a fully dead motor. An attorney on this thread commented on a 2015 Tesla Model S: "This is a known issue with older Model S/X cars, yes. A 2015 is HIGHLY at risk of that. Also, a INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION

Filed Feb 14, 2024 · Transmission · MA

The contact owns a 2016 Tesla Model S. The contact stated while driving 25 MPH and coming up on a fork in the road, the autopilot system was not activated, the vehicle suddenly veered to the right independently, requiring the contact to quickly redirect the vehicle towards the intended route. Later, during a separate incident while driving at an undisclosed speed, the vehicle inadvertently lost all motive and electrical power. The contact was able to coast to the shoulder of the roadway, where the vehicle was able to restart. The contact also stated that she had previously become aware that there was condensation building inside the instrument panel as well as the center display and that the dealer had been notified but failed to address her concern. No warning lights were illuminated. The vehicle was taken to the dealer, who was unable to duplicate the failure, insisting that the autopilot system was likely activated. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was unknown.

Filed May 9, 2022 · Engine, Fuel system · CA

On April 9th, 2022, the vehicle in traffic went from the drive gear to the park. vehicles were coming behind me at 55mph and I could not maneuver to safety. It took up to 4mins before I got moving. The incident occurred again on April 25th, while my kids and I were on the way to basketball practice. Finally, I got an appointment with Tesla service, and after two weeks of troubleshooting I was informed that the issue is an anomaly.

Filed Jan 18, 2022 · Transmission · CA

Some versions of Model S and X front drive unit halfshafts might cause excessive vibrations during hard acceleration at higher ride height settings. If the drive shaft fails while driving on the freeway then it will not be safe especially with kids in the car. Tesla needs to add this on their recall list. Please see service bulletin https://cdn.motor1.com/pdf-files/sb-21-39-001-replace-front-drive-unit-halfshafts.pdf