Synthetic ATF is a no brainer - am I correct?

[yummy88]

I just switch to Mobil 1 ATF and I have been reading up on ATF. It appears that what kills transmission is the heat. The heat destroys the fluid and once the fluid loses it ability lubricate the transmission pretty much self destructs. Am I right?

Why the heat? Heat can be from towing, city driving, driving in mountainous area, severe driving or in older transmission, slipping or worn out clutches etc.

It is well known that synthetics have a higher tolerance to breakdown when compared to convention oils

So would it not be a no brainer to switch to synthetic ATF, especially for older cars (slipping/worn out clutches). Transmission might run hotter, but synthetic ATF will resist breakdown and if ATF is ok then transmission is ok.

Now if you transmission is running 100 percent then regular ATF would do. But many of us have cars with over 100K so the transmission is bound to be slipping a little so synthetic ATF IS the way to go.

DO I make sense?

Now if you car asks for specific ATF like Toyota Type 4 then you do not have a choice but you should cut the ATF service intervals to ensure condition of ATF. Maybe 15K service vs recommended 30K service.

 

[JHZR2]

My understanding is that while temperature kills transmissions, for a normal, gently driven AT, heat isnt as big an issue as additive depletion.

I know a number of people who believe on
JMH

 

[unDummy]

Yes, synthetic ATF is a no brainer. Even the automakers recently figured that out

But, the best way to control heat is by upgrading the cooler.

Frequent changes bring the viscosity back up since cheaper fluids shear quickly. It'll also remove any wear suspended in the fluid. Proper filtration is something that many transmissions still lack.

 

[yummy88]

A cooler or even a larger cooler will help reduce heat and prelong the life of the transmission. I used to have an old highway patrol car and it even had a small power steering fluid cooler.

But I am looking from the point that with everything being equal an aging transmission that is slipping slightly or somehow generating more heat will do well with synthetic ATF and an even larger cooler.

If this is true then the whole idea of not changing ATF on older transmission is a misnomer. In fact when transmission is getting old, one should use definately use synthetic ATF and shorter D&R schedule to combat the increased heat. And doing so can easily increase lifespan of the aging transmission.

I notice that with public awareness of the 3K oil change and increase in outfits like Jiffy Lubes (yes sometimes they strip the oil plug)many cars are now doing 150K or even 200K and running fine at that mileage. In fact at 200K the trouble is no longer engine failure but transmission failure.

 

[alreadygone]

As transmisions age clutch packs wear and seals harden untill they don't seal as well. Even worn clutch packs don't slip untill ready for rebuild. If it's not slipping follow reasonable service schedule (either factory or less if under severe service conditons, which most are). If there is ANY slippage, save your money for rebuild. Then, with new guts synthetic would be a good idea.

bob

 

[1040 WreckerMan]

If the transmission is slipping, then no fluid will "fix" the problem. That is, unless the problem that caused the slipping was from incorrect fluid in the first place. Mostly the heat is generated when the torque converter is in fluid coupling mode, commonly referred to as converter, instead of lockup.

Syn ATF is great. IMO the best thing for an automatic is frequent fluid drains. I put drain plugs in all the pans and I drain the pan at anywhere from 10K to 30L miles depending on application. This not only keeps the viscosity at the correct level, but that the FM also stays close to the correct level. A cooler and a spin on ATF filter are also very helpful.

 

[Winston]

Quote:

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I notice that with public awareness of the 3K oil change and increase in outfits like Jiffy Lubes (yes sometimes they strip the oil plug)many cars are now doing 150K or even 200K and running fine at that mileage. In fact at 200K the trouble is no longer engine failure but transmission failure.

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You are not really a 3k oil changer are your?

It is not the 3k oil changes that make the engines last longer. It is technology of todays oils that allow the engines to last so long.

 

[yummy88]

I change the oil myself and use the 3K as a target. This means that after factoring procrastination, weather,NFL, NBA on TV, it gets done around 5K or so.

I have a Toyota Avalon (120K) and a Volvo 940 Turbo (150K) both using German Castrol and Mobil 1 ATF

I also have a 92 LS 400 (200K) using Havoline conventional 10w40 oil. Bought it at 190K and former owner used dino so I stuck with dino.

 

[PT1]

Quote:

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My understanding is that while temperature kills transmissions, for a normal, gently driven AT, heat isnt as big an issue as additive depletion.

I know a number of people who believe on
JMH

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Correct, once the friction modifiers are gone...you will have issues.

 

[Whitewolf]

You have to be careful what you mean by synthetic. In NA synthetic can be PAO but it can also be Group III. Not that that is a bad thing, some Group III formulations are actually better in oxidation than some PAO/ester formulations (there, now I've gone and upset someone again!).
PT1 is correct though, it doesn't matter how good the baseoil is if the fm system in the add pack is shot.