Synthetic trans. fluid

[trever1t]

I was thinking of changing my tranny fluid to a synthetic. I drive it hard and figure it might help maintain it.

Someone told me it was not a good idea because of the "too slick for the clutches" theory.

Anyone have any experience or feedback?

[asepgrad98]

Someone told me it was not a good idea because of the "too slick for the clutches" theory

 

Hah thats a good one. The ATF must pass many tests before they can put "Dexron III" on the label including the "slickness". Go buy some Mobil 1 ATF and be happy.

[Bish]

Might be a good one but I know of 2 cases where it was a problem. I had 2 friends change to Mobil 1 and immediately started to get increased tranny slippage in their 4L60E. Went back to Dino and the slipping went away in both cases. Having said that, I have also heard of people switching with no problems.

 

My opinion and my tranny guy's opinion are stay away from synthetic is you have a close to stock trans. Just an opinion though so take it for what it's worth. I just change the dino regularly.

[BADGERMAN]

Been running Royal Purple Synthetic in my trans for about a year.

No problems at all.

[asepgrad98]

I just change the dino regularly.

 

If you can get your trans drain plug to work then just drain the 3-4 qts out every other time you change your oil and youll be fine.

[averagehonky]

Mine started slipping. I'll be going back to dino.

[plainvanilla]

I was thinking of changing my tranny fluid to a synthetic. I drive it hard and figure it  might help maintain it.

Someone told me it was not a good idea because of the "too slick for the clutches" theory.

Anyone have any experience or feedback?

 

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Just like the myth that synthetics are too slick to break in a motor.

When Mobil 1 is factory fill in over 10 high performance cars.

 

ATF is built to spec. Dexron 3, Chrysler ATF Plus 3 & 4, Toyota and Honda all have to meet the lubricity and friction moditication test.

The only real difference is the base oil used to hold the additives. ATF is basically a 10 wt hydrualic oil. The base stocks for the synthetics with higher VI's flow better and faster in cold temps and handle the heat better than group 1 or 2 base stocks.

 

It is better, but your still gonna have to change the filter sooner or later.

If you plan on keeping the vehicle awhile and you want to invest the extra $$, then I say go for it.

[trever1t]

What about the guys above who tried it and actually have issue?

 

I agree that the use of synthetics should be superior.

Synthetics are Not really slicker anyway, just able to keep viscocity longer.

[05Silverado81]

I know when you just pull the plug not all of the tranny fluid comes out. Can I mix synthetic and the stock dino or will I have to flush it and put all synthetic?

[Bish]

I just change the dino regularly.

 

If you can get your trans drain plug to work then just drain the 3-4 qts out every other time you change your oil and youll be fine.

 

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Bingo. I got my drain plug to work by replacing the one I destroyed with a new one. I do exactly that, every 10K (every oil change) drain and fill. ATF is cheap and it stays REALLY clean that way.

 

Don't get me wrong, I'm a huge fan of synthetics as I run them anywhere I can.....excpet a stock trans. I also agree it SHOULD be better at reducing temps, and surviving high temps and high mileage better than dino. But......when the person I just handed almost $3K for a built trans and torque converter that has been building performance tannies for 20 years tells me he has never had good luck with synthetics in an auto and STRONGLY recommends dino with regular changes, I tend to listen.

 

To those that are running it, great! I would probably be running it myself were it not for a few stories I was told. If it works, all the better!

 

Ragarding 05Silverado81's question, yes you can mix if you have to but I would think a flush would be better to exchange it all. You could do the old home made flush. Pull the pressure cooler line at the Rad and put end into a 5 gallon plastic container with 1 gallon increments marked. Start the engine and let it fill to the 1 gallon mark. SHut it off and put in 4 qts ATF. Start it until another gallon goes through. Shut off and then repeat once or twice more and you should have 99% of fluid exchanged. The return line is not under vacuum so it won't suck new fluid out of another container and you don't want your tranny to run dry.

[Black02Silverado]

This like engine oil can be debated for ever. You can mix synthetic with regular ATF. I have noticed that more problems tend to come to life if the transmission was not taken care of properly. By this I mean they didn't change the fluid out untill it was already dark or had well over 40k miles on the original fluid.

 

My understanding is if you change out old fluid like that with any new ATF be it synthetic or not then you went from an oil that was full of contamination and possibly thicker due to the particles and such in the fluid. Once you change it now it is cleaning out the system and is a thinner fluid and slipping issues arise. That is my understanding of it. I changed out a friends 89 chevy pickup, it was getting dark and he didn't know the true mileage on it but the truck has 198k. It started slipping after the change out of just 5qts. I used regular ATF not synthetic. He went and bought an automatic transmission additive called Tranny Honey. Put that in and it has been running fine since. Why? Not sure other than it added some viscosity to the fluid.

 

I feel if you take care of your tranny, change it on a regular basis like every 30k you will not have issues. But if you live in the extreme cold and heat as well as haul and tow then a good synthetic is cheap insurance and well worth the cost.

[fyarbrou]

Unless you are frequently pulling, I don't see the need to run the $ynthetic ATF. I had rather drain and replenish a few quarts of ATF every 2-3 oil changes or so. This is easy to do and is less stressful on your transmission. The synthetic ATF is probably superior but the standard ATF is fine too. I believe that the key is regular maintenance and to prevent fluid contamination no matter what you use.

 

I would DEFINETLY not switch to a synthetic ATF or oil if the vehicle has 60K or better on it. You are asking for problems at that point.

[plainvanilla]

...Synthetics are Not really slicker anyway, just able to keep viscocity longer.

 

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Bingo! Less resistance to flow and wider operating temps because the molecules have been all selected to be about the same size and shape.

[hcvone]

I changed my trans fluid (all my fluids) to Amsoil synthetics at the first oil change, I do this to all my cars/trucks, never had any problems.

[willfxp]

I'm not going to run syn because I am going to have the dealership do a flush (and I doubt they have Mobil1). I had one at 60k, and will probably get another one done at 120k.

 

On my Saturn, I can drain almost 80% of the fluid from the transmission. At 105k or so, I put in Mobil 1 Syn, and it runs great. No problems.