The best way to settle this dispute is for some to not change it and others change it and I'll place my bet on the one's that change it for the purpose of longevity.
Lifelong trans oil is a much more dangerous a statement than "100k plugs". My plugs were absolute toast at 85k and I got a bump in power and mileage when I tossed those shits.
What the Heck is a Sealed Transmission? -
"What the Heck is a Sealed Transmission?
Over recent decades, the technology in automobiles has grown increasingly complex. Automakers have invented a new era of car maintenance in the name of “making life easier.” Modern car manufacturers have gotten into the swing of creating so-called “life-time” parts, and transmissions are no exception. From SUVs to sports cars, routine transmission maintenance has grown more complicated, and vehicle owners need to know a few things about sealed transmissions.
I know of a guy with a G35 who claims he hasn't changed coolant, trans fluid or power steering fluid for something like 175k miles. You could roll the dice, especially if you live in an area like this guy with no extremes in temps from summer to winter, no hills/mountains to climb, very low dust, decent humidity and not desert dry, etc.
The manufacturer needs their customers to come back to "the company store".
Why Does the Transmission Fluid Need to Be Replaced?
As time goes by, metal shavings from the gears in the transmission will become prominent in the transmission fluid. Historically, automakers recommended the change of transmission fluid every 60,000 miles. However, today’s automakers have gone against this claim for a few reasons. Some of the hypothetical reasons for this change include the following:
Government organizations are pressuring automakers to create better, longer-lasting parts.
Sealed transmissions help to reduce the amount of “bad” transmission fluid being disposed of.
Engineers have been charged with creating equipment to function longer, without necessarily redesigning the basic function.
Additionally, some believe automakers have implemented this change as a means of reducing the potential work for independent mechanics, such as transmission repair shops.
How Does the Fluid Get Replaced?
A sealed transmission does need to have the fluid checked or replaced periodically. Although this may seem like a waste of time, the potential consequences of not having this vital part of a vehicle checked can easily rise into the hundreds, if not thousands, of dollars. Auto techs can check the fluid of a sealed transmission through an access in the side of the transmission. Some may opt to remove the transmission pan to completely replace the transmission fluid, as well as the gasket.
Can You Check the Transmission Fluid of a Sealed Transmission at Home?
For the do-it-yourself vehicle owners, attempting to replace the transmission fluid in sealed transmission should not be attempted. A minor mistake could lead to permanent damage. Furthermore, some automakers may void repair warranties if an unlicensed mechanic attempts to open the transmission housing.
How Do You Know if Your Sealed Transmission Has Bad Fluid?
Poor transmission fluid quality will usually lead to one of the following signs:
The sound of gears grinding when driving or switching gears.
Delayed engagement of the gears, such as when placing the vehicle in “reverse.”
Delayed shifting of the gears when accelerating, i.e. the engine revs without increasing in speed.
Fewer drivers are keeping their vehicles for extended periods of time.
As automakers become increasingly aware of profit margins and the need to produce longer-lasting vehicles, the “sealed” concept will expand to other parts of the vehicle. One day, vehicle owners may not even have to worry about checking the oil. Until then, vehicle owners need to understand what a sealed transmission is and how to prevent the premature failure of a sealed transmission. If you do not see a transmission fluid dipstick, you probably have a sealed transmission. Above all else remember anything in a vehicle could break, even if the automakers believe it will last forever."
Let's call it
"planned obsolescence"
I love this guy. One corny SOB but he's got great energy. I like that he's holding up a bottle of Valvoline Max Life at the end of the vid.
Now, just cause ADHD Scotty says so don't make it so but to me, it's common sense IF you want to keep the car for a long time.