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Automatic Transmission Drain/Fill, Flush Concerns.

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Darkbloodmon

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This was a shower thought so go easy on me.

To my understanding the reason why you shouldn't drain/fill or flush an automatic with high miles is the risk that the suspended clutch material will cause the clutch packs to slip and not grab if its removed from the fluid and replaced with new clean fluid.

My thought : Depending on the fluid color on the dip stick (should be red or pink for most ATFs) it would be better to do a drain and fill from the dipstick after the vehicle has been sitting for a while to let anything heavy settle. Pulling fluid out with a fluid extractor at the dipstick tube (if it has one) and then filling it at the same port would minimize the chance of removing the worn friction materials. While pulling the fluid out you could also measure the amount to put back in.

The pivoting detail being the condition of the fluid on the dipstick, if its clear and clean there is less risk than if you pull the dipstick up and it looks like engine oil nearing the time for an oil change.

This could be done repeatedly to ween the transmission back to "cleaner" fluid and or a serviceable maintenance schedule.

Thoughts?
 
Na, the problem isn't the stuff that is suspended - it's the stuff the settled especially within the valvebody.
The new fluid with all the good new cleaning property's tend to break some of this stuff loose and send it on its way downstream. And there the problem starts.

But also, this is not a problem with a transmission that was regularly serviced - it's one with trannys where an owner didn't take care of and let the soup in for 100k or even longer.
Which are most of the time anyways close to the end of their service life for that reason.
 
Had this happen on a Caravan a few years back. Van was what the new driver in the house was driving. It was maintained but due to age and mileage, trans started acting up after a trans service. Was able to buy a little bit of time with an additive that helped with clutch slipping. Problem is that if you're having this issue or it comes up after servicing the trans, A complete rebuild or replacement will be needed along with complete flush of the lines and cooler for the trans. As @Ozymandias has stated, the new fluid does it's job of cleaning the gunk! That's way you need to flush all components of the system. Was able to get a few more years out of van after putting in a trans and having flushed system! Was taken out of service from another driver! Maintenance, maintenance, maintenance is the best medicine! I think most of us on the forum here understand that point and try to follow that rule. We brought these trucks knowing that was an extra expense required! Enjoy these rigs! Get the dust off and drive!!! :D
 
Na, the problem isn't the stuff that is suspended - it's the stuff the settled especially within the valvebody.
The new fluid with all the good new cleaning property's tend to break some of this stuff loose and send it on its way downstream. And there the problem starts.

But also, this is not a problem with a transmission that was regularly serviced - it's one with trannys where an owner didn't take care of and let the soup in for 100k or even longer.
Which are most of the time anyways close to the end of their service life for that reason.

Wouldn't fluid color and condition be an indicator of how much suspension of worn material is in the fluid system?
 
In my humble opinion NO. But you can take a fluid sample of the Transmisson oil and have that analyzed by a lab to find the condition and any suspended material if in question.
 
Lucas oil Stop Slip ATF additives are essentially a friction modifier similar to LSD additives with high viscosity right?
 
If we could live in a world of absolutes it'd be a beautiful thing(To me at least). I'll take an indicator over a shot in the dark any day.

Dully noted.

The point is you can have nasty fluid with no buildup, and clean fluid with buildup.


Lucas oil Stop Slip ATF additives are essentially a friction modifier similar to LSD additives with high viscosity right?

Stay away from ATF additives, just use good fluid.
 
Regulare maintenance is the key, I'm always happy when the fluid that I drain looks and smells exactly the same as the one that I put in. This is my indicator.
Because then, that's my opinion, I had no wear and tear on the transmission components.
 
55K + on this AMZ/OIL ATF. Visual indicator trans is doing well at 65K on the clock. My 11 DRW 68rfe at trade in. All I did was drain the pan and remove it and take the pic. Did NOT pour any fluid and filings out of pan. This is towing 29k combined over 1/2 the miles.

DA53CB2D-16DF-4F8E-9E7E-CFA16BAB58C9.jpeg
 
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Regulare maintenance is the key

Believe me I understand that. What I'm getting at though with this thread is a way to get vehicles that haven't been on a maintence schedule back on one. Not every vehicle with X transmission is going to be worth the attempt. For example a Nissan CVT, or Chrysler(Stellantis) CVT.

Chances are if you've bought a used car from a private seller or dealership with an Automatic and asked about the transmission service history you'd get looked at like a deer in headlights or fed some BS about "Certified Pre-owned"

The mass majority of vehicles on the road are automatics. The mass majority of vehicles on the road aren't maintained at the recommended service intervals.
 
If purchasing a vehicle from private seller, if they can't provide me the receipts to show service, I'd offer a lower price! Most people understand vehicle maintenance ( I say this while waiting for the pile on) and the ones that understand that keep records of it. When buying from a dealer, was this a customers vehicle and are there service records? Fresh fluids could be a signal off hiding something unless the mileage adds up correctly with fluid change. I always pop some trim panels to look for water damage and that will tell you how well interior has been kept or cleaned just before selling. Look for the little things to tell you about how the vehicle has been kept. Golden color on dipsticks can tell you about fluid changes, antifreeze condition and of course the most overlooked item is brake and power steering fluid (if not electric p/s). Buying any used car can be a "chance", just try and find issues before committing to the purchase like will they allow you to take to "your" mechanic. I can say that the 2 vehicles that we've had in our household with a CVT have been flawless! The first went over 225K before it was totaled and the other has over 80K and still going. (Dodge Caliber, Mitsubishi Outlander Sport) I had dealer do the Caliber trans service. I've done the Outlander service. Last time at Mitsubishi dealer, they made comment about trans having that amount of miles on it without needing work! I told them that we don't use the paddle shifters which are know to cause the solenoids to die and cause trans to have to be rebuilt. Sorry about long post, but wanted to provide my input. Caliber was bought new, Outlander had 23K+ when purchased.
 
There is no way that I could provide all the receipts for the maintenance on my truck in the 145,000 miles on the OD. I usually buy three or four filters at a time from Geno's and buy my oil from Sam's club which will last for a year at a time. Since I buy 6 gallons at a time (I don't worry about price chasing the last dime in savings) from Sam's. But I do have a spread sheet listing all of the maintenance, mileage and date when preformed plus unit cost of items bought. Major repairs receipts have been kept such as front end rebuild and so forth but greasing and oil changes, filter changes for the most part no.
 
There is no way that I could provide all the receipts for the maintenance on my truck in the 145,000 miles on the OD. I usually buy three or four filters at a time from Geno's and buy my oil from Sam's club which will last for a year at a time. Since I buy 6 gallons at a time (I don't worry about price chasing the last dime in savings) from Sam's. But I do have a spread sheet listing all of the maintenance, mileage and date when preformed plus unit cost of items bought. Major repairs receipts have been kept such as front end rebuild and so forth but greasing and oil changes, filter changes for the most part no.

I was in the same situation with receipts on my last 2 CTD’s, but on the ‘22 I am keeping a stack of receipts.
 
Geno's will email you your order history. They did when I had to prove maintenance on the AISIN same with AMZ/OIL. Order history on AMAZON is always available. I also keep a log of all maintenance in the back of the owners manual.
 
I appreciate the feedback, I'll keep it in mind as I tread carefully.

Previously I did an unintentional drain and fill(Amsoil OE ATF) on our 98' 4Runner 4x4, A340F trans 4SAuto, 290K. Good fluid color, filter not replaced, no issues since; its a daily driver.

Today I did an extract and fill(Amsoil SS ATF) on my 91' Accord, H4A trans 4SAuto, 125K. Good fluid color, no issues since, filter not serviceable since it's built into the case.

I have a friend with an 06' Element, BZKA trans 4SAuto, 335K, fluid color is dark, he wants to try a drain a fill at some point after he gets a second vehicle. No running issues as is. I'll try the same process as I did on mine.

Both Honda's are a bit different in that they're "Semi-Automatics" not automatics. Similar to HD Semi Auto's in class 8s they are built like a manual transmission with gears, leavers and forks and they use electronic controlled hydraulic actuated external solenoids to push the rods/forks. Majority of Honda's have Honda built/designed transmissions due to Borg Warner holding a vast array of patents/copyrights.

I wouldn't try this on any vehicle. But its something I want to explore. I don't like the ultimatum that if it hasn't been serviced by the previous owners you've got a ticking bomb.
 
Believe me I understand that. What I'm getting at though with this thread is a way to get vehicles that haven't been on a maintence schedule back on one. Not every vehicle with X transmission is going to be worth the attempt. For example a Nissan CVT, or Chrysler(Stellantis) CVT.

Chances are if you've bought a used car from a private seller or dealership with an Automatic and asked about the transmission service history you'd get looked at like a deer in headlights or fed some BS about "Certified Pre-owned"

The mass majority of vehicles on the road are automatics. The mass majority of vehicles on the road aren't maintained at the recommended service intervals.

There is no way to keep the new fluid from doing it's job, cleaning.

But also not every transmission is a time bomb just by not doing the maintenance, if the vehicle was used carefully, old lady yes, it can go a long time without.
 
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