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Tesla Model S Drive Unit Replacement by the Numbers
During my early days of researching the Tesla Model S, I had concerns about a number of things that were emerging in the press. Fires, Model S drive unit issues, and handling in the snow. Tesla quickly addressed the “firegate” issue by retrofitting the Model S with a titanium shield. My concerns around winter driving, in particular handling in the snow, also became a non-issue after watching several winter driving videos put together by Bjørn Nyland.
Within no time, I became a new Model S owner and quickly learned that driving in the winter could actually be quite fun with a good set of winter tires. Tesla later introduced the all-wheel drive “D” models putting to rest any remaining doubt that the Model S could be the best and safest handling car in the world.
But one question still remains for me, Has Tesla dealt with the Drive Unit issues?
Model S Drive Unit Replacement by the Numbers
There is a group of Model S owners across the forums, but also validated by major publications such as Edmunds, that have had one or more drive unit replacements.
Early reports of drive unit issues ranged from total failures that left the Model S inoperable, to more recent complaints of clunking and milling noises. Elon has said in the past that many of these pre-emptive drive unit replacements were unnecessary and a simple $0.50 shim was all that was really needed, yet Tesla Service centers have been proactively replacing drive units.
The following polls from TMC show that a majority of Model S owners have had their drive units replaced.
While the poll only represents a small sample of Model S owners, one might draw significance in the numbers as the density circles around owners needing a drive unit replacement at relatively low mileage, and without any harsh driving prior to failure.
The polls also give insight to the motive behind each drive unit replacement.
Though it appears the issues mainly center around earlier versions of the Model S, there’s been reports of newer Model S with Autopilot hardware hearing milling noises coming from the drive unit. One viewer described the sound as “sawing wood”.
Tesla’s Response to Drive Unit Issues
In typical Tesla fashion, the company acted fast to address the issues, and curb concerns by offering an unlimited mile/8 year warranty on the drive unit. I think this was a great response by Tesla which put to rest any concerns about the quality and long term durability of their drive units.
Elon is now talking about building a power train that will last a million miles and I believe Tesla continues to put significant energy into improving the drive units. Tesla continues to honor the warranty and is proactively replacing drive units that show early signs of problems.
My Experience
After 12 months of Model S ownership and 30k miles drive, I started hearing a humming noise from the rear of my Model S during highway cruising. The noise was unusual as I had gotten used to hearing only the noise of the tires and wind, but there was a new noise only noticeable when cruising or decelerating with regeneration at 65 MPH and over. The noise continued to become more audible over the next few months, but I learned to live with it and did not contact Tesla. My personal rule of thumb on noise related issues is to wait for passengers to comment on it first. It’s my self crazy check.
Two months after the original drive unit humming noises began, a higher pitched milling type noise started occuring when traveling at speeds of 20 MPH or less. The sound varied depending on how much power was being used. That’s when I reached out to Tesla.

Tesla service record
Tesla service had me come in for a test drive which they can do on demand without you needing to wait. We drove about a block before the Tesla service technician said the drive unit needed to be replaced.
The explanation was that tolerances inside the drive unit have led to metal particles getting into the fluid around the drive unit, and as the concentration of particles increased, it caused the noise from the drive unit to become louder when under load. The new drive units evidently have better tolerances and are less prone to having metal particles being shaved off.
At that time, Tesla service has been very backed up here in Massachusetts so my appointment for the drive unit replacement was scheduled six weeks out. I put on another 4,000 miles during that wait time, with an increasingly louder drive unit, before it was finally replaced.
When Tesla replaces a drive unit, they replace both the drive unit and inverter as you can see from a copy of the parts list. The last letter in the drive unit part number (“M” in my case) seems to indicate the generation of the drive unit. The later the letter the better, with the “Q”s seeming to have the best longevity according to the forums.
I’m happy to say that I’ve logged 8,000 miles of happy and noise-free driving after my drive unit replacement. The replacement was done recently so my guess is that I have a newer unit, and thus hope this will be my only replacement.
Thankfully for all of us, Tesla has a first class warranty and level of service. While it goes without saying that inconveniences such as this may happen, rest assured that Tesla has you covered and will always strive to make things right.
Investor's Corner
Tesla stock tumbles after earnings, one of its sharpest single-day declines
Tesla stock (NASDAQ: TSLA) endured one of its sharpest single-day declines in years on July 23, tumbling approximately 14.5 percent and closing near $320 after opening the session around $374. The drop erased more than $140 billion in market value amid heavy trading volume and left the shares at multi-week lows.
The sell-off followed the company’s second-quarter 2026 results, released the previous evening. Tesla reported record revenue of $28.2 billion, up 26 percent year over year, driven by a Q2-record 480,126 vehicle deliveries. Energy storage deployments also rose strongly.
Tesla (TSLA) Q2 2026 earnings results: miss on EPS, beat on revenue
Yet profitability disappointed sharply. Operating income fell 57 percent to $398 million, compressing the operating margin to just 1.4 percent. Non-GAAP earnings per share came in at $0.33, well below the roughly $0.53 analysts had expected. Free cash flow turned negative by $1.1 billion as capital expenditures surged 142 percent to $5.8 billion, largely tied to accelerated spending on artificial intelligence, robotics, and autonomous systems.
The losses on capex were expected, as Tesla said it would be spending heavily in 2026.
Investors also reacted to lingering uncertainty surrounding key product timelines. During the Earnings Call, management reiterated ambitions for Robotaxi deployment and the Optimus humanoid robot, but offered limited new concrete milestones, renewing questions about execution pace that have long accompanied Tesla’s ambitious roadmap.
The magnitude of the decline places it among Tesla’s more severe one-day percentage losses since its 2010 initial public offering. Historically, the two largest single-day drops (split-adjusted) remain September 8, 2020, when shares fell 21.1 percent amid broader market volatility and valuation concerns, and January 13, 2012, with a 19.3 percent plunge during the company’s early growth struggles.
Other notable declines include an 18.6 percent drop on March 16, 2020, at the onset of pandemic-related market turmoil. Thursday’s move ranks roughly ninth on the all-time list but stands out as the steepest in more than a year.
Despite the short-term pain, Tesla’s long-term trajectory has repeatedly recovered from such volatility. The latest results underscore both the strength of its core automotive and energy businesses and the near-term costs of heavy investment in next-generation technologies.
Elon Musk
Elon Musk is not happy about this Tesla Full Self-Driving approval delay
Elon Musk clapped back at France’s decision to withhold the approval for Tesla’s Full Self-Driving (FSD) Supervised system, projecting a clear and blunt message to French Transport Minister Phillippe Tabarot, after he publicly rejected the technology in its current form.
Tabarot outlines several concerns with Tesla Full Self-Driving in a detailed video statement, where he said, “The safety trade-offs are not yet sufficient to authorize it as it currently stands,” he said. He emphasized that FSD is not a true self-driving system and that the driver remains fully responsible.
Key issues Tabarot also brought up included allowing speeding when surrounding traffic exceeds limits and what he believes are insufficient guarantees of driver attention during complex urban maneuvers such as lane changes, intersections, and roundabouts.
Delaying the approval of FSD in France will cost lives
— Elon Musk (@elonmusk) July 22, 2026
While acknowledging technological progress and France’s support for autonomous innovation, Tabarot stressed that deployment must prioritize road safety. He noted ongoing technical discussions with Tesla, the Netherlands, and other European partners, with further ecosystem meetings planned for the fall.
Musk’s rebuke highlights the human cost of regulatory caution. Tesla’s latest safety reports provide compelling data supporting accelerated adoption. In the most recent 12-month period, vehicles using FSD (Supervised) recorded one major collision per approximately 5.1 million miles driven, dramatically better than the U.S. national average of one crash per 698,000 miles.
Even Tesla vehicles driven manually with active safety features outperform the average by a wide margin. These figures come from billions of real-world miles of telemetry, showing FSD vehicles involved in far fewer incidents than both manual Teslas and the broader U.S. fleet.
Critics argue Tesla’s comparisons require careful scrutiny regarding reporting thresholds and fleet demographics, yet the data consistently positions FSD as a potential lifesaver. With road fatalities remaining a leading cause of death worldwide, Musk contends that proven safer technology should not face prolonged bureaucratic hurdles.
France’s measured approach reflects the broader European regulatory caution, which many, especially Musk, have been critical of in the past. However, as autonomous systems from Tesla and competitors like Waymo demonstrate superior safety in independent studies, pressure is mounting for harmonized approvals.
Musk’s warning carries the belief that every month of delay may equate to avoidable tragedies on European roads.
Investor's Corner
Google’s massive stake in SpaceX will shock you
In a striking revelation that underscores the lucrative crossover between Big Tech and space exploration, Alphabet Inc., Google’s parent company, disclosed a massive $94.1 billion equity stake in SpaceX following the rocket company’s blockbuster initial public offering earlier this year.
The disclosure came in Alphabet’s quarterly filing, marking the first time the long-held private investment has been publicly valued at market prices. Google was an early backer, investing alongside Fidelity in 2015 with roughly $500-900 million at a time when SpaceX was valued around $12 billion.
That bet has delivered extraordinary returns, roughly a hundredfold, transforming a strategic play on satellite internet and launch capabilities into one of Alphabet’s largest assets.
Google, $GOOGL, has said they hold $94 billion in SpaceX, $SPCX, shares after IPO.
— unusual_whales (@unusual_whales) July 23, 2026
Of the total holding, approximately $80 billion remains subject to short-term post-IPO lockup restrictions, preventing near-term sales. An additional $14.1 billion faces longer-term restrictions, extending into the third quarter of 2027. This structure limits immediate liquidity but protects against market volatility as SpaceX transitions into public trading.
The SpaceX position contributed significantly to gains in Alphabet’s broader investment portfolio, which also includes a major stake in AI leader Anthropic. Combined, these holdings helped drive nearly $100 billion in investment gains during the second quarter, providing a substantial boost to net income amid ongoing AI spending pressures.
Analysts view the disclosure as validation of Alphabet’s venture strategy beyond its core search and cloud businesses. The investment aligns with deeper ties, including reported multi-billion-dollar deals for AI computing capacity on SpaceX infrastructure. As SpaceX advances Starship flights, Starlink expansion, and ambitious Mars goals under Elon Musk, Google’s stake positions it to benefit from the commercialization of space.
For Alphabet, the windfall highlights how patient, forward-looking bets in transformative sectors can yield outsized rewards. While lockups temper short-term impact, the holding cements SpaceX as a cornerstone of Alphabet’s diversified portfolio in an era where aerospace, AI, and connectivity increasingly intersect. Investors will watch closely as restrictions lift and SpaceX’s public performance unfolds.


