Changing the Oil (the experts are wrong)

Mendel

Senior Member.
I like this as an example how it doesn't take a conspiracy theory to think "I know what I saw, the experts are wrong".

Please watch this short video, it's only 1:38 minutes.

Source: https://youtube.com/shorts/8uBFyVWuWsw

It's about someone who changes the oil in their differential, filling it up to the hole, and finds that the amount given in the manual is wrong. The video demonstrates this clearly.
Commenters pointed out that the method only works correctly when the car is level, but the car in the video is not.
The author admits that he raised a wheel up to get a better camera view, which tilted the car, raised the hole, and led to him overfilling the differential. The manual was correct, after all.
When you think you've found an error in well established knowledge, it's usually the best course of action to figure out what you got wrong.

This was a very shallow rabbit hole, and the video's author escaped easily.
But mentally, the attitude of taking "I've found something wrong" un-self-critically (or trusting people who have this attitude) is tempting, and should prompt everyone to triple-check the evidence and their understanding of it,
 
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When you think you've found an error in well established knowledge, it's usually the best course of action to figure out what you got wrong.
Given that I don't know of a "quart" such that two of them are 1.8L, my first guess was that the units on his bag-o-lube were different from the ones in the manuals (2 US quarts is 1.89L, so to 2 s.f. is "1.9L").. However, he is treating 3.8 pints as interchangeable with 2 quarts, so small disparities like that wouldn't be relevant.

However, I still think that he should fill it with the intended volume of liquid, not fill it till it spills out; as when he levels the car he'll have over-filled it. So he's double boobed, IMHO. However, I've never owned a car and all I know about differentials is the difference between Leibniz and Newton's notation.
 
However, I've never owned a car and all I know about differentials is the difference between Leibniz and Newton's notation.
What kind of lubricant do you use for these? Midnight oil? ;)

However, I still think that he should fill it with the intended volume of liquid, not fill it till it spills out
That is the intended amount—when the car is level.
 
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I like this as an example how it doesn't take a conspiracy theory to think "I know what I saw, the experts are wrong".

Except when the experts might actually be wrong. The thing about conspiracy theories, at least good ones, is there is some amount of truth involved. The guy in your video thought the experts at Ford where wrong in their recommendations for the diff oil, but what about the case of the General Motors experts possibly being wrong in their recommendations for engine oil?

In 2019 GM revamped its 6.2l small block V8 engine, calling it the L87. It employed various strategies to maximize fuel mileage, at least as much as one can in a 6.2l engine, including direct injection, progressive cylinder deactivation (running on anything between 2-8 cylinders as needed) and specking a thin 0W-20 oil. The lighter oil results in less friction, and supposedly results in slightly better gas mileage.

Then the new L87s started to fail:

External Quote:

The NHTSA Safety Recall Report shows GM's investigation included 28,102 complaints about the engine failure and 14,332 allegations of propulsion loss. GM also identified 12 potentially related crashes causing 12 injuries.
https://niada.com/dashboard/gm-issues-recall-for-600k-vehicles-with-6-2l-v8-engines/

One of GM's solutions was to change the oil specified for the engine (bold by me):

External Quote:

Amid an ongoing federal investigation into the 6.2-liter's potential catastrophic failure, the automaker is once again recommending that owners use a new kind of engine oil. The updated guidance is the second change for the L87, with the first intended to address a massive recall in April 2025.

That original recall, which followed an initial investigation by the National Highway Traffic Safety Administration (NHTSA), was upgraded to a full-scale recall of nearly 600,000 L87-equipped models. The fix, according to GM at the time, was to swap the V-8's original 0W-20 weight oil with a heavier Mobil 1 Supercar 0W-40 oil. According to a report by GM Authority, General Motors has now issued a new bulletin to dealers changing the recommended oil again, this time to Mobil 1 FS 0W-40.
https://www.caranddriver.com/news/a70288921/gm-oil-change-recommendation-changes/

The real culprit seems to be defective rod bearings and crankshafts that gets exacerbated by the thin oil, but even if one's engine is inspected and found to be defect free, the new oil specifications still apply (bold by me):

External Quote:

The recall was released in response to a supplier-related issue involving potential rod bearing contamination and crankshafts that may be out of spec. Per the recall procedure, every impacted vehicle must undergo an inspection, and from there, will be divided into one of two categories: those units that require a full engine replacement, and those that pass inspection but receive a revised oil spec and service procedure.

For owners whose L87 engines were inspected and did not need a full replacement, the oil change spec is the primary corrective action.
https://gmauthority.com/blog/2026/0...nreplaced-engine-with-0w-40-oil-doing-so-far/

So, the experts specified light weight 0W-20 oil originally which helped contribute to catastrophic engine failure and an eventual recall. The solution was to change the specifications to heavier 0W-40, but that might mean the advertised fuel mileage will be lower. In addition, one could get the idea GM is in full CYA mode with all of this (bold by me):

External Quote:

GM's 6.2L V-8 engine was first introduced in model year 2019 and is used in some of its top-selling models. The automaker has been aware of problems for some time. Shortly after its debut, customers complained of unusual noises, power loss and no-start conditions.

GM launched its first investigation into the problem in February 2022. Two additional investigations followed, which were closed in June 2023 and July 2024, respectively. Based on the available information GM had at the time, the root cause was not initially identified, according to the NHTSA recall report.

The fourth investigation, which was initiated by GM after the NHTSA opened its probe in January 2025, used an updated field data analysis to identify a suspect build period: March 1, 2021, to May 31, 2024. According to the recall report, 6.2L V-8 engines manufactured between these dates showed a higher rate of failure claims.
https://www.wardsauto.com/news/nhtsa-opens-investigation-gm-engine-failures-prior-recall/

So, after 3 internal investigations didn't really go anywhere, a 4th investigation, after the NHTSA started an external investigation, finally figured something out. The original 6.2l engines had a 5 year/50,00 mile warranty.

Is it conspiratorial thinking to suggest GM was stalling a bit, maybe trying to run out the 50,000 mile warranty on at least some of the vehicles with a number of inconclusive investigations? The final investigation reportedly had "updated field data", so one could argue that allowed them to arrive at a solution. And they did offer an extended warranty for inspected engines:

External Quote:
Engines that pass inspection will also receive a new special coverage program that extends warranty protection for 10 years or 150,000 miles from the vehicle's in-service date, whichever comes first.
https://gmauthority.com/blog/2025/0...od-engines-to-get-extended-warranty-coverage/

Where the experts wrong in recommending the 0W-20 oil? It's likely they knew nothing about the defective bearings and cranks, at least at first, and they were tasked with gaining every bit of mileage possible, so the decision may have made sense at the time. But, even engines that are deemed to not have the problematic defects are now to use the heavier 0W-40 oil. Are they saying the 0W-20 was too light and never should have been used in the first place? Are they saying the inspected engines should be defect free, but maybe not, so use the heavy oil just in case? Can one trust their different positions and changing recommendations? Is this a conspiracy to cover up what's really going on? ;)

I'm not a conspiracy minded person, but when I was looking to replace my 12 year old work truck last year with something more for a retired person, did I consider a GM? Not a chance.
 
Except when the experts might actually be wrong.
But note the course of events didn't start with "a guy in his home garage discovers a secret". The oil change issue is one that, if wrong, thousands of mechanics would have encountered before, because the DANA 50 is not new. The issue you're describing is so complex that the actual experts couldn't find anthing wrong with the first investigations, and the final investigation likely involved data from a great number of observations, not one anecdote of "my car broke, therefore GM designed it wrong". It involved other experts, too.

Note also that I didn't write "I've found something wrong" is always unjustified. It's just that the odds are against you (in a well-established circumstance), and you should act accordingly.

The radio just reported there's a wrong-way-driver on the interstate, but they got it wrong, there's hundreds of them!

The thing about conspiracy theories, at least good ones, is there is some amount of truth involved.
The "truth" in these is almost always ripped out of context and made to serve the overarching misinformation.

9/11? Truth: the towers collapsed.
Chemtrails? Truth: aircraft leave white clouds in the sky.
UFOs? People see things they can't explain.
Flat Earth? The Earth is almost flat.
Moon landing was faked? There was a moon landing.
Vaccines? They can have side effects.
Lizard people? .....
Elvis is alive? He was.
The 2020 election was stolen? Trump lost.

The "truth" in these conspiracy theories is the window dressing for the rabbit hole, nothing more.

It's true that this guy put more oil in his differential than he ought to have been able to.
It's his theory that explains it (the shop manual is wrong) that lacks truth.
Just because the starting point is true doesn't mean the rest of it is.
 
The manual was correct, after all.

Correct yes, but possibly also lacking. Did the manual specify all the the relevant conditions to be met when changing the oil, including the levelling requirements? If it didn't, and if I were auditing this 'non-compliance', I would trace the problem which fooled a, let's say, naive user, back to the manual itself. I would recommend the manual to be checked for all the places where relevant test/procedural conditions are not clearly specified (I bet there will be a lot more :cool:) and then be amended.
 
Correct yes, but possibly also lacking. Did the manual specify all the the relevant conditions to be met when changing the oil, including the levelling requirements? If it didn't, and if I were auditing this 'non-compliance', I would trace the problem which fooled a, let's say, naive user, back to the manual itself. I would recommend the manual to be checked for all the places where relevant test/procedural conditions are not clearly specified (I bet there will be a lot more :cool:) and then be amended.
Yup, all the blocks fit through the square hole.
 
But note the course of events didn't start with "a guy in his home garage discovers a secret". The oil change issue is one that, if wrong, thousands of mechanics would have encountered before, because the DANA 50 is not new. The issue you're describing is so complex that the actual experts couldn't find anthing wrong with the first investigations, and the final investigation likely involved data from a great number of observations, not one anecdote of "my car broke, therefore GM designed it wrong". It involved other experts, too.

Agreed. I guess when I saw your post, I was transported back to late February of last year. My 12 year old work truck was acting up, and while we managed to fix it (new turbocharger and variable fin controller), it was a fair bit of work only to have it throw codes for a NOx sensor in the overly complicated catalytic DEF injection system. All a few weeks before our annual trip to Baja, which is 1700 miles round trip. Maybe it was time to look at trucks.

As I still prefer a 3/4 ton (250/2500 depending on the make), that means the big 3, Ford, GM and Chrysler/FCA/Stellantis or whatever they're calling themselves now. So, I "did my own research" :D. This would have been just after GM had opened its NHTSA inspired 4th investigation in January '25 and just ahead of the April full recall. The reports of catastrophic engine failure were known, as was the shift to a heavier oil, but IIRC, the exact cause wasn't.

While much more complicated than the guy with the diff oil, there was a sense of "cover-up" in some of the writings and YouTube videos I perused at the time. With some of the YouTube mechanics opining that the recommended oil was way to light for the expected duty loads of the engine. Not quite they discovered the experts were wrong, but close.

The more conspiratorial minded guys made a point of blaming the Biden administration (of course) for imposing unrealistic mileage requirements resulting in the use of the light weight oil and complicated cylinder deactivation systems. This ignored that RAM and GM had been using deactivation systems for 10-15 years.

I think your post got me thinking about what sort of conspiratorial ideas appeal to whom and when. I, probably like you and most of us here, never got the 9/11 conspiracy. What was the point? Same with Chem-trails, what's the point? These are overly complicated scenarios that people seem to then create reasons for. They see a lot of contrails, get convinced they're chemtrails and then come up with various reasons for them. Everything from sterilizing the population, to mind control, to poisonous aluminum to whatever else. They always seem backwards to me, first a conspiracy then any number of explanations for why the conspiracy exists.

But with the idea of improper oil in the engine helping to cause catastrophic failures really coming to light just as I was truck shopping, got me wondering. Did GM know more than they were telling? Where they hiding something, and if so why? Well, to save money is an obvious explanation. Fix engines under warranty as needed and hope the rest last long enough to go out of warranty, then it's the customers problem. Change the oil recommendations to maybe keep more of the engines going a bit longer.

Was I being conspiratorial? Yeah, maybe, but I would argue delaying or hiding problems to save money isn't all that far fetched. It was just an interesting look back prompted by your post. Are we all susceptible to conspiratorial thinking given the right circumstance?
 
Correct yes, but possibly also lacking. Did the manual specify all the the relevant conditions to be met when changing the oil, including the levelling requirements?
It doesn't matter, the correct amount is the correct amount. If the guy had put that in, he wouldn't have had to take any out afterwards.

The fact that the "fill up to the hole" rule of thumb no longer works when you tilt the thing is basic physics; if you've ever used a teapot, you should be aware. If you don't understand that, you have no business tinkering with your car in the first place.
 
Was I being conspiratorial? Yeah, maybe, but I would argue delaying or hiding problems to save money isn't all that far fetched. It was just an interesting look back prompted by your post.
You are definitely not being conspiratorial. There is a long and disturbing history of this behaviour in the automobile industry,

External Quote:

Source: https://www.youtube.com/watch?v=wH7ymdMPTJA

The VW Dieselgate scandal (a "defeat device" shipped by VW such that 11 million vehicles could fraudulently comply with emissions standards) may appear out of place in the list above. Yet the dramatic increase in pollution from that vast number of vehicles can be statistically linked to higher mortality rates.

Article:
May 28, 2025 (The Guardian) The excess pollution emitted as a result of the Dieselgate scandal has killed about 16,000 people in the UK and caused 30,000 cases of asthma in children, according to a new analysis. A further 6,000 premature deaths will occur in coming years without action, the researchers said.

This is a more recent Japanese data fabrication scandal not mentioned in the video:

Article:
TOKYO, June 3, 2024 (Reuters) A safety test scandal at Japanese automakers widened on Monday, with Toyota Motor and Mazda both halting shipments of some vehicles after Japan's transport ministry found irregularities in applications to certify certain models.

The irregularities were also found in applications from Honda Suzuki and Yamaha Motor, the ministry said. The automakers were found to have submitted incorrect or manipulated test data when they applied for certification of the vehicles.

When it comes to producing safety and quality control test reports and certifications, for some, the temptation to copy-and-paste will always be there. Prevention is better than the cure. Such behaviours must be disincentivized with effective leadership and training, efficient tools and procedures, and by NOT pressuring people to meet impossible timelines.
 
You are definitely not being conspiratorial. There is a long and disturbing history of this behaviour in the automobile industry,
How many of the incidents on your list are coverups?
I know the VW diesel thing is, but I looked into the Toyota accelerator affair and it seems to be a "honest mistake" kind of deal?
 
Toyota's deceptive handling of the safety problems in its vehicles (unintended acceleration that was either caused by Floor Mat Entrapment or Sticky Pedals) from 2009 to 2010 resulted in a record penalty of USD 1.2 billion in 2014.

Due to the suspicions raised, subsequent investigation by NHTSA and NASA of Electronic Throttle Controls was also undertaken, but found no evidence of defects in 2019.

Article:
US DOJ, Press Release March 19, 2014

Toyota Motor Corporation Admits to Misleading Consumers and U.S. Regulator About Safety Issues Related to Unintended Acceleration in Its Cars


Independent Monitor to Be Appointed to Oversee Toyota's Public Statements and Reporting of Safety Issues

U.S. Attorney General Eric Holder, U.S. Secretary of Transportation Anthony Foxx, U.S. Attorney for the Southern District of New York Preet Bharara, Inspector General of the U.S. Department of Transportation (DOT) Calvin L. Scovel III, National Highway Traffic Safety Administration (NHTSA) Acting Administrator David Friedman and Federal Bureau of Investigation (FBI) Deputy Assistant Director Joe Campbell announced a criminal wire fraud charge against Toyota Motor Corporation ("TOYOTA" or "the company"), an automotive company headquartered in Toyota City, Japan, that designs, manufactures, assembles, and sells Toyota and Lexus brand vehicles. The charge is that TOYOTA defrauded consumers in the fall of 2009 and early 2010 by issuing misleading statements about safety issues in Toyota and Lexus vehicles.

Also today, the Department of Justice announced a deferred prosecution agreement with TOYOTA ("the agreement") under which the company admits that it misled U.S. consumers by concealing and making deceptive statements about two safety issues affecting its vehicles, each of which caused a type of unintended acceleration. The admissions are contained in a detailed statement of facts attached to the agreement. The agreement, which is subject to judicial review, requires TOYOTA to pay a $1.2 billion financial penalty – the largest penalty of its kind ever imposed on an automotive company, and imposes on TOYOTA an independent monitor to review and assess policies, practices and procedures relating to TOYOTA's safety-related public statements and reporting obligations. TOYOTA agrees to pay the penalty under a Final Order of Forfeiture in a parallel civil action also filed today in the Southern District of New York.
...
In the fall of 2009, TOYOTA deceived consumers and its U.S. regulator, the National Highway Traffic Safety Administration ("NHTSA"), by claiming that it had "addressed" the "root cause" of unintended acceleration in its vehicles through a limited safety recall of eight models for floor-mat entrapment, a dangerous condition in which an improperly secured or incompatible all-weather floor mat can "trap" a depressed gas pedal causing the car to accelerate to a high speed. Such public assurances deceived customers and NHTSA in two ways: First, at the time the statements were made, TOYOTA knew that it had not recalled some cars with design features that made them just as susceptible to floor-mat entrapment as some of the recalled cars. Second, only weeks before these statements were made, TOYOTA had taken steps to hide from NHTSA another type of unintended acceleration in its vehicles, separate and apart from floor-mat entrapment: a problem with accelerators getting stuck at partially depressed levels, known as "sticky pedal."
...
On Oct. 21, 2009, however, in the wake of the San Diego floor-mat entrapment accident, and in the midst of TOYOTA's discussions with NHTSA about its eight-model entrapment recall, engineers at TOYOTA and the leadership of TOYOTA's recall decision group decided to cancel the design change instruction that had already been issued and to suspend all remaining design changes planned for A-Pedal Company pedals in U.S. models. U.S. TOYOTA subsidiary employees who had been preparing for implementation of the changes were instructed, orally, to alert the manufacturing plants of the cancellation. They were also instructed not to put anything about the cancellation in writing. A-Pedal Company itself would receive no written cancellation at this time; instead, contrary to TOYOTA's own standard procedures, the cancellation was to be effected without a paper trail.

TOYOTA decided to suspend the pedal design changes in the United States, and to avoid memorializing that suspension, in order to prevent NHTSA from learning about the sticky pedal problem.
 

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