2016 Tesla Model S Powertrain & Transmission Problems

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.

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.

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

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.

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.

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

I backed my tesla out of my driveway on 12/17. I could see as I backed into the street another car at the stop sign waiting to turn left. I was blocking part of the road so as the car was in reverse moving back, I put my tesla in "D". I clearly saw the D. I stepped on accelerator seeing they were patiently waiting and I wanted to get out of their way. As I touched gas I was in shock-I kept going in reverse! The car dash said "D" and in my shock i pressed down on the gas more. I ended up accelerating more in reverse and smashed right into a parked car on the street! I knew I was swerving back and steered into the middle of the street I thought. I never heard the warning sign on my car because it was in D. I didnt see the car in my rearview mirror and in the shock of the speed and my correct into the middle of the road, I dented my neighbors front left bumper only. Thankfully I didn't damage their lights. It only did a small scrape in the front right rear side of my model S. I did replicate the problem one more time on camera about 15 minutes later. But I was in such shock the camera drops below the road so it has my voice on it and I didn't want to hit someone else again. This is very dangerous to accelerate backwards when the dash says "D". I've taken the tesla in many times for the screens freezing. They say its memory issues and want me to pay 2500 to upgrade the internal parts. This puts my kids and anyone at risk if they're behind me when Im shifting to drive and drive off. There again were no warnings before the crash because the car was in D.

THE TESLA MODEL S PURCHASED, HAS BEEN RECEIVED WITH MULTIPLE SAFETY CONCERNS. 1) SUPENSION FORE LINKS & ALT LINKS NEED REPLACEMENT DUE TO CORROSION 2)POWER STEER FAULT - RIGHT TOE LINK HAS EXCESSIVW CORROSION & WEAR REPLACEMENT NEEDED. 3) RIGHT AXCEL BOOT LEAKING, CLEVIS MOUNT, RIGHT & LEFT AXEL REPLACEMENT REQUIRED. TOTAL LABOUR EXCEEDS OVER $9,000. THIS VEHICLE ORIGINATED AND MANUFACTURED IN USA WAS IMPORTED TO CANADA. THERE ARE SAFETY CONCERNS BEYOND THIS, THE VEHICLE IS UNSAFE AND FEATURES MANY CONCERNS. DRIVING ON RESIDENTIAL ROADS THE SUSPENSION DROPS UNEXPECTEDLY, DURING HIGH SPEEDS THE VEHICLE PULLS TO THE SIDE. PARKING ASSIST & PARKING BREAK INACTIVE. VARIOUS SUSPENSION CONCERNS LEAVE THIS "LUXURY" VEHICLE PARKED IMMOBILIZED.

TL* THE CONTACT OWNS A 2016 TESLA MODEL S. THE CONTACT STATED THAT A YEAR AGO, WHILE TRYING TO EXIT THE PARKING LOT, THE GEAR WAS PUT IN DRIVE, HOWEVER, THE VEHICLE ACCELERATED BACKWARDS AND CRASHED INTO THE VEHICLE BEHIND. THERE WAS NO INJURY. THERE WAS NOT POLICE REPORT. THE VEHICLE WAS DAMAGED BUT WAS NOT TOWED. THE FAILURE THE AIR BAG DID NOT DEPLOY. THE RECURRED RECENTLY AS THE CONTACT ATTEMPTED TO PARK BETWEEN TWO VEHICLES THE VEHICLE WENT IN REVERSE AND CRASHED INTO THE VEHICLE ON THE LEFT. THE CONTACT WAS NOT SURE OF ANY WARNING. THE DEALER WAS NOT CALLED IN EITHER CASES. THE MANUFACTURER WAS NOT MADE AWARE OF ANY OF FAILURES. THE VEHICLE WAS NOT REPAIRED. THE FAILURE MILEAGE WAS APPROXIMATELY 33,000.

THERE ARE MANY TESLAS IN THE WRECKING YARDS WITH BROKEN FRONT SUSPENSIONS. OWNERS ARE COMPLAINING ON THE FORUMS OF VIBRATION PROBLEMS THAT ARE CAUSING DAMAGE TO THE DRIVE SHAFTS. TESLA SEEMS UNABLE TO FIX THIS PROBLEM AND IT MAY BE CREATING A RISK OF SUDDEN FAILURE. HTTPS://TESLAMOTORSCLUB.COM/TMC/THREADS/FRONT-VIBRATION-WHEN-ACCELERATING-ACCELEROMETER-GRAPHS.72268/PAGE-2 SAMPLE: @MMCCORD UNFORTUNATELY REPLACING THE HALF-SHAFTS DID SOLVE THE PROBLEM BUT ONLY FOR ONE MONTH. THE VIBRATION CAME BACK. AFTER FOUR ATTEMPTS BY THE SC TO FIX IT THE CAR STILL HAS THE VIBRATION. NOW THAT YOU MENTIONED HIGH SETTING NOW I CAN REPLICATE THE PROBLEM EVERY TIME. IT ALSO EXPLAINS WHY ONLY IN SOME CIRCUMSTANCES I GOT THE VIBRATION. MY DRIVEWAY IS A BIT HIGHER THAN THE MAIN ROAD SO I HAVE THE SUSPENSION SET TO HIGH WHEN I ARRIVE HOME. WHEN I USUALLY LEAVE BEFORE HITTING A HIGHER SPEED ROAD THE SUSPENSION WILL STAY TO HIGH. THE MOMENT I PULL INTO A HIGH SPEED ROAD ( > 35 MPH, WHICH IS THE THRESHOLD FOR STANDARD SETTING), EVEN A MILD ACCELERATION WILL CAUSE THE SHUDDER. I HAD THE FOLLOWING WORK DONE: FRONT RIGHT HALFSHAFT - DUAL MOTOR (1030616-00-A) FRONT LEFT HALFSHAFT - DUAL MOTOR (1030615-00-A) FRONT JACKSHAFT ASSEMBLY - DUAL MOTOR (1030632-00-A) SDU RE ALIGNMENT FRONT DRIVE UNIT MOUNTING BUSHES ADJUSTING NONE OF THAT SOLVED THE PROBLEM OR SOLVED IT FOR A COUPLE OF WEEKS. MY CONCLUSION IS THAT THE CAR DOESN'T BODE TO WELL WHEN TRANSITIONING FROM HIGH TO STANDARD SETTING WHILE YOU ACCELERATE MILDLY OR STRONGER. I USE IT DAILY AT LEAST TWO LOCATIONS AND NOW IT EXPLAINS WHY I AM GETTING THE SHUDDER AFTER LEAVING IN EXACTLY SAME SPOT. AND YES IT WILL WEAR THE HALF SHAFTS PREMATURELY. ANYONE HAD THIS PROBLEM FIXED FOR GOOD? MY SC SEEMS CLUELESS AND THE WHOLE SITUATION IS EMBARRASSING FOR THEM REALLY. *TR

THE ?STALLING? PROBLEM HAPPENED TO MY MODEL S SINCE I STARTED TO DRIVE THE NEW CAR IN 03/16. I GOT KICKED FROM ?D?/?R? TO ?P? AT BEGINNING STAGE WHEN I START TO PRESS THE ACCELERATOR, AROUND 50% OF THE TIME WHEN I STARTED OR CHANGED MY SITTING POSITION. THE PROBLEM WOULD STOP AFTER I ADJUST MY SITTING POSITION/POSTURE SEVERAL TIMES. I REPORTED TO TESLA ROADSIDE SERVICE SEVERAL TIMES IN 04/16. THERE WAS NO SOLUTION ON-LINE, I HAVE NEVER GOT ANY FOLLOW UP FROM TESLA AS PROMISED. I TOOK MY CAR TO SALES AGENT [XXX] IN BETHESDA, MD. HE COULD NOT SOLVE MY PROBLEM, SUGGESTED TO GO TO SERVICE SHOP IN ROCKVILLE, MD. THE STALLING PROBLEM BECOMES A HAZARDOUS ISSUE WHEN IT HAPPENED ON THE ROAD, ESPECIALLY IN SLOPPED BUSY INTERSECTIONS. ON 05/13/16, I TOOK MY CAR TO SERVICE SHOP IN ROCKVILLE MD. THE ENGINEERS CHECK OUT SYSTEM & RECORDS. THEY VERIFIED STALLING HAPPENED IN THAT MORNING, & CLAIM THERE WAS NOTHING WRONG WITH CAR/SYSTEM. THE PROBLEM WAS ?NOBODY WAS SITTING ON THE DRIVING SEAT? WHEN STALLING HAPPENED. THEY WANT ME TO KEEP RECORDS. IT WAS STUPID IGNORANCE & IRRESPONSIBILITY. ON 06/11/16, I SENT COMPLAINT TO SERVICEHELPNA SERVICEHELPNA@TESLA.COM I GOT RESPONSE THE NEXT DAY, KICK ME BACK TO WHERE I CAME FROM: [XXX], ?. I AM SORRY YOU HAVE HAD THIS EXPERIENCE WITH YOUR VEHICLE. THE BEST PERSON TO ADDRESS THIS, GET IT RESOLVED, AND ESCALATE THE ISSUE IF NECESSARY, WOULD BE THE LOCAL SERVICE MANAGER. I HAVE REACHED OUT TO THEM AND ASKED THEM TO LOOK INTO THIS ISSUE ON YOUR BEHALF AND HAVE THEIR TEAM FOLLOW UP WITH YOU. ? IVANחנ BERGMAN | TECHNICAL SUPPORT SPECIALIST IT IS 06/17/16. I HAVE RECEIVED NOTHING FROM TESLA. THE STALLING PROBLEM PERSISTS. INSTEAD OF KEEPING BEING KICKED AROUND BY TESLA, I BRING MY COMPLAINT TO NHTSA [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). *TR