Change dino ATF to synthetic?

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97 Toyota Avalon 152K. Been using dino ATF since day one. ATF changes every 30k. Never had any problems whatsoever. Want to drive the car until it dies. Put a Magnefine on 6k ago. I recently put RP in the differential (separate from the transmission)--can't tell any difference plus or minus.

Time to flush the ATF--anyone see any issues with changing to synthetic? Is it really worth the $8-$10 per quart? Is a high mileage ATF worth the extra money?? Am I trying to fix something that isn't broken?
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There is no risk in changing to synthetic ATF. Since you've got a magnefine on it, you're keeping the regular ATF a lot cleaner than others.

The full synthetics are worth the cost if you use them for their extended drains, such as Amsoil ATF for 75,000-100,000 miles between flushings. Mobil 1 ATF is around $6 a quart at the local Wal-Mart, and around $7-7.50 at the local Advance, Auto Zone, etc.

If cost is a factor, Dexron-VI can be found for less than $6 a quart and would be a better option than regular Dexron-III/Mercon. I wouldn't blatantly state that Dexron-VI will outlast any synthetic Dexron-III, but I would say the two are at least on-par with each other in terms of heat resistance, cold flow, deposit formation, etc.
 
what type (brand) of atf have you used up to this point. Have you done flushes or drains every 30k? If you do flushes, are they performed at the dealer?
 
Product information on Dexron-VI states that it lasts twice as long as the Dexron-III it replaces. I imagine this is in regards to heat damage and shear stability.

So if you changed Dexron-III at 30K, you can go to 60K with Dexron-IV.
 
there is something to say about synthetic ATF, I nursed a 1st-2nd gear hard shifting mitsubishi mirage 4 speed ELC trans for 8 years.
 
This is an old and pretty high mileage transmission. Don't expect DexronVI to make it last twice as long. If anything, it already has lasted a lifetime.

30k drain/refills is nothing to brag about. But, it is better then the maintenance many vehicles get. I would just continue what you are doing. If you want to spend more money, then use a blend(MerconV/DexVI) or full synthetic(Ams/RL/RP/M1...). If not, then any Dex/merc is good enough.

Regardless of fluid chosen, since flushes aren't being performed, I would definitely shorten the drain/refill interval in 1/2.
 
I have done Mobil 1 synthetic ATF and most recently Castrol Dexron VI ATF in my GM made transmission. Car shifts fine, especially in hot and cold weather. While I drain and fill every 30,000 miles, my mechannic says I can go longer.

I recommend synthetic or dexron VI as part of an overall maintenance routine. It at the very least gives me peace of mind.
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30k mile drain and fills isnt enough imo.. esp if you drive a lot of city miles or short distances.. i change mine every 15k or every 3rd oil change..
 
Roll your eyes all you want. Show me a battery 30k UOAs and ATF services that all look good, with no wear, minimal shearing, clean magnets, spotless filters......

City driving and short trips require a more aggressive maintenance plan. Drving style, transmission type and family, fluid chosen..... are all some variables that need to be considered. But, you can never go wrong shortening an interval for 'partial' maintenance, especially if you plan on keeping the car forever and don't want the $3k Aamco/Cottman expense.
 
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Roll your eyes all you want. Show me a battery 30k UOAs and ATF services that all look good, with no wear, minimal shearing, clean magnets, spotless filters......

City driving and short trips require a more aggressive maintenance plan. Drving style, transmission type and family, fluid chosen..... are all some variables that need to be considered. But, you can never go wrong shortening an interval for 'partial' maintenance, especially if you plan on keeping the car forever and don't want the $3k Aamco/Cottman expense.




thank you dummy.. atf fluid is cheaper than a transmission are ANY transmission work so thats why i do what i do
 
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Roll your eyes all you want. Show me a battery 30k UOAs and ATF services that all look good, with no wear, minimal shearing, clean magnets, spotless filters......



I won't waste my time on UOAs that only give a small part of the picture. As they say, a little knowledge is a dangerous thing.

Autos aren't designed to last forever. They are designed with a targeted service life in mind, usually 150-200k miles. While some units may last 300k, but the vast majority of them will only surpass the targeted service life. Some units may not even last the targeted service life. Changing the fluid more often than recommended will not make the unit last "forever," if it wasn't designed to in the first place.
 
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Autos aren't designed to last forever as you say later in your post so I'm confused by your statement (typo I assume). However, undummy specifically said "keeping the car forever". 150-200k miles is not 'forever', even if not meant literally, to most folks myself included. AT work can be reduced with more frequent changes on partial maintenance. I do pretty much agree that following OEM intervals will get you to their definition of forever, however ugly that may be.

Also, UOAs do only provide a small part of the picture to most folks, but throw Terry into the mix and you get some real info you can work with including longevity.
 
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AT work can be reduced with more frequent changes on partial maintenance. I do pretty much agree that following OEM intervals will get you to their definition of forever, however ugly that may be.



As an engineer, I was hoping that you'd back up your statement with some credible evidence. If you design a unit to last 200k miles for instance, no amount of fluid changes and delicate care will allow it to last 300k, every single time. The unit just wasn't designed to last 300k in the first place.

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Also, UOAs do only provide a small part of the picture to most folks, but throw Terry into the mix and you get some real info you can work with including longevity.



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No unit is designed for anything other then to statistically make it past the warranty period within the defined warranty budget whatever that may be. Maybe an accountant from the auto mfg'ers can explain how they figure the accrual out for each vehicle. Trust me, it isn't what the engineers would like and it is not in the best interest of a consumer who plans on keeping a vehicle a long time.

Nothing is designed to last forever.
But, you can exceed the ANY design requirments with the variables that YOU DO control: preventive maintenance, improved filtration, better cooling, quality fluids, common sense driving style... And, since this is BiTOG, and not a auto-manufacturer controlled website, I'll concentrate on pushing "PM" and upgrades as much as possible, which are proven to work. No maintenance, or lack of, is proven NOT to work. Common sense doesn't need engineering backing it up. Credible evidence pulls into the warranty bays and independent shops regularly.

Critic, you don't waste your time with UOAs? but you do post there don't you? Why don't you waste your time and volunteer at an Aamco or other transmission shop? Maybe your opinion on the superiority of OE engineering will change, as it needs to since some of your posts show thoughtless thinking.

A UOA along with filter/magnet inspection shows plenty, without professional interpretation, and is a pretty big picture!

Also, NOONE knows what those components are truly designed for. With the number of early failures, and common or frequent failures, makes you wonder what the h3ll is going on. And some automakers wonder why they aren't making money, or are not selling tons of cars, or wonder why depreciation is pathetic with certain models?
 
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Critic, you don't waste your time with UOAs? but you do post there don't you? Why don't you waste your time and volunteer at an Aamco or other transmission shop? Maybe your opinion on the superiority of OE engineering will change, as it needs to since some of your posts show thoughtless thinking.





Critic believes in UOA, he's just too cheap to pay for them. Just like with OCI oil and transmission.
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i still have to agree with dummy on this.. if you service and really take care of your vehicle i think it really can help nix some internal damage that can happen when you dont do preventive maint.. now whether syn compared to dino can really prolong the life of something is totally up in the air but i think the qualities of syns can help a little more esp when overheating, sheering and other issues that arise simply bc it can take the abuse a little better therefore perhaps prolonging the life of the atf and or motor
 
"...every single time?" Mike you're killing me. Surely you jest. No amount of fluid changes and delicate care will allow the transmission to make it to the, for example, 200k mile design objective every single time either. That's why the OE has a warranty/recall fund. Your statements are beginning to be a little whacky. What does me being an engineer have to do with anything? I don't work for any OEM/supplier or even as a designer so I don't have any design data or goals. Just as one point, the units are tested with the OE fluid - not some of the aftermarket fluids that can be much better.
 
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