ATF Lacks Cleaning Detergents

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j91z28d1

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I'm no chemist so I can't back this up with anything but a life time of working on cars.. atf will clean just about anything. I used to hate changing tranny filters on our fleet of c6 trannys because it's always a mess but when you're done and you wash the atf off, your hands are the cleanest they will be till the next time you do it lol.

I believe this is where the flushing comes from. if you've ever changed a tranny pan gasket and been covered with the stuff you'll see how it somehow breaks down years of oil build up from old school leaky engines.



I'm not going to argue about if it work or not, as said I've got nothing but my own experience and you will either believe it on not. but for anyone curious about it, this guy is good with these gm trucks and talks about how to do it correctly. it's not a toss a few qt in and go type of thing.




if your engine is decently clean, this isn't needed. this is for those crazy bad ones that probably should be rebuild. not a normal thing to do for sport like when people toss in a can of sea foam. both my ls engines have over 100k on them and are spotless inside and they have had nothing special done to them and no need for a atf flush. but if i picked up a used one full of gunk, I'd do it.
 

Marky Dissod

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Not disputing anything, just starting to wonder if the above applies more to Dex3 instead of Dex6?
'cause GM changed the formulation, and all?
 

Z15

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Dexron-VI is such a tough spec to meet, I think it can only be met with high grade PAO synthetic oil in high quantity.
Dexron VI IS NOT a pao synthetic. Its what is referred to as a Group III base stock, PAO is Group IV

Nothing GM branded is PAO.

The highest grade Dexron is Dexron HP in the 8-sp and Dexron ULV in the 10-sp

What are GTL Base oils?
They are synthetic paraffinic base oils obtained using Fischer-Tropsch Synthesis of natural gas.

GM Dexron HP

"The base stock of old fluid (19355656) has the ability to attract low levels of moisture, which can cause degradation of the coefficient of friction of the fluid. The new fluid (19417577) has a new GTL (Gas to Liquid) base stock that is able to tolerate more moisture. Shuddering transmissions and torque converters have been recovered with the new fluid. New transmission fluid tests have been developed due this issue to prevent it from occurring with new transmission fluids."
 

Z15

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Don't some people put ATF in the engine crankcase to 'flush' it clean?
Never said that makes sense, just sayin' that I've heard that some people do it.
The concern of using an ATF in place of a flush is chemical incompatibility with engine seal material. ATF has been known to over swell engine seals and cause leaks and premature failure.
 

tom3

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Used to use ATF in five speed manuals as listed in owners manuals. The Tremec TKO was originally spec'd to use ATF. I wonder if the new stuff would be better, or worse, in high pressure gear sliding contact and good syncro action?
 

Marky Dissod

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The highest grade Dexron is Dexron HP in the 8L90E
Is Dexron HP 'backwards' compatible with Dexron 6J?
By which I mean, is it okay to pour Dexron HP into my 4L60E - or would it be a mistake?

(PLEASE do not construe the above to mean that I WILL use Dexron HP in MY 4L60E!
Just wondering if this is a bad, so-so, meh, or good idea for anyone?)
 

j91z28d1

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Used to use ATF in five speed manuals as listed in owners manuals. The Tremec TKO was originally spec'd to use ATF. I wonder if the new stuff would be better, or worse, in high pressure gear sliding contact and good syncro action?

it's my opinion that atf is a horrible manual tranny even when it's called for unless you're not going to drive it in any kind of way that is ******* synchro. it is to slippery and isn't thick enough to cushion between fast shifts.

you can't use old school gear lube because what's in it will eat up the glue on the friction material on the synchro. back in the days of the fox body mustang guys trying to push the limits of stock T5 trannys. which called for atf, they would put the old thick stp engine treatment stuff in them. it made shifting a bit harder but helped keep 3rd gear in them on the drag strip.


these days I run redline MTL in all my manual trannys that call for atf and they run cooler and shift better on track days. (not drag strip) but I've head good things about gm synchromesh fluid too.
 

Just Fishing

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Interesting.
I attempted to use it to break up carbon a while back, it might have helped a little but not enough.

Then I get introduced to this Mopar+4 ATF, it has an almost gear oil stink to it.
I used that to break up carbon on the jeep engine rebuild.
I don't know if it helped, but I had a really easy time getting the carbon off of the pistons when using it.

It also did a great job removing light rust from Fastners.
 

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