No, you’re right. Transmissions are different from engines.
But this concept of a magical slurry of transmission fluid with clutch material ground up in it keeping a transmission working... I just don’t buy it.
Imagine it on a bigger scale. Would you expect your rear differential to work well if the teeth were ground down to nubs and the ground off teeth bits were floating in the gear oil? No, that’s a recipe for disaster.
If your clutch material has worn off into the fluid, I would expect it would do a better job at wearing off more clutch material than it would providing the required friction. Once it’s off the clutch, it’s debris and should be removed.
A neglected transmission is just that: a neglected transmission. It is on borrowed time.
Now, I will 100% agree that flushes are bad. But I also think that engine and coolant “flushes” (where they add chemical A and run it x miles) are bad.
Proper service is to drain the old, refill with new. Don’t pump anything, don’t use high pressure, etc. Just drop the pan, take a bath in transmission fluid, and refill with new.
(Repeat after so many miles to get more of that old fluid out of the torque converter.)
Unfortunately that's not how it works. We also can't compare Transmission clutch packs to rear differentials which don't need friction to move the car.
Also your later comment about people complaining that after 50,000 miles they did a flush and their transmission went out would not occur either because 50,000 miles is way too early an interval to be in the situation that is being discussed. When I say hi mile neglected or abused transmission we are referring to one with well over a hundred thousand has never had the fluid changed. My theory and practice has always been anything under 85k is okay to do what you want. Even the flush it and hurt it.
But take one with 185k and the results can end up not being good.
You can say you don't buy it all you want but I have personally seen it happen a decent number of times so I do have some personal experience with the matter.
Of course with Transmissions changing some over the years we have to admit not all designs are going to work the same even if they used to.
The magic clutch dust holding them together you mention... I will remind you that the old used car lot trick to make a transmission move a car and stop slippage was to put sawdust into the transmission.
Many people are not aware of this because it happened in the past and it wasn't something I told people about.
Any old mechanic knows about the phrase sawdust in the transmission.
You have to remember also that on let's say a 4-speed transmission with overdrive, overdrive is almost always the first gear to start slipping.
It only takes three or four decent slips and the faces of the clutches can be polished so they won't grip anymore.
As I said before, if a flush or even a pan drop in fluid change causes one to go out quickly then it was on its last legs anyways but the point is... Sometimes those last legs can last a year or two under normal conditions.
Take the same vehicle and not change the fluid and do a few burnouts or let someone new drive the car who is really hard on it, get stuck in the mud and have to spend the tires back and forth, or tow a heavy trailer one time and the transmission would probably fail the same timeframe it failed after the flush.
I'm just telling you for a fact that often a flush is the straw that breaks the camel's back. Fewer timed a fluid change and pan drop is the straw but it can still be the straw.
There were even mechanics on high mile dirty fluid who would strain and filter the fluid and put it back in because they feared putting new back in would cause it to slip. I feel this is over-the-top cautious and as we've talked about, if it's going to go from just the fresh fluid then it's on its way out anyways so take your chances.
Also, back to the magic dust holding them together, actually, giving the friction so the car can move... that's what many of the additives like loose Lucas transmission stop slip does. Some even mention polymers and stuff but they just try to thicken up the fluid and make it less slippery so it can move the car easier.
Regarding your last post, it is very true that a lot of people don't seriously consider or they don't do any service to the transmission until they experience a symptom. So whether or not they changed the fluid, flush the Floyd or not Donna. Their transmission had already acted up and it might have been going to further mess up and stop moved in car in a week or two anyways. So regardless of whether they just change the fluid or flush the fluid and it goes out , it obviously had issues to start with.
I have, however, been involved with a handful that were experiencing no symptoms but had failures shortly after flushes. These were on cars that myself or friends purchased used and had no idea of any of the history other than the current condition of the Floyd. None of these were experiencing any symptoms but after a flush within two to three weeks the transmission started slipping.
After a few of these, I was able to convince my one friend who is OCD about maintenance and fluid and Amsoil Etc to stop doing transmission flushes and go back to pan drops and fluid changes.
If we were to want to do some scientific or at least a numeric evaluation, I would venture to put good money on a bet that if you took 100 cars with a hundred and fifty thousand miles on them whose fluid has never been changed and flushed half of them but pandrok and fluid changed or left the other half alone... I would bet a much higher and noticeable percentage of the Transmissions flushed would have failures and need to be rebuilt or replaced before 225000 miles.
I have had plenty of Ford 4 speed automatic transmissions go 250 plus thousand miles and never have the fluid changed.
