Do syn ATF fluids "clean" like motor oils do?

[Kira]

dailydriver said of ATF..."WHY do the 'old school' mechanics suggest dumping a quart into the sump of a push rod engine with stuck/noisy/even collapsed hydraulic lifters??"

It's old fashioned for sure because the older ATF had some kind of solvent in it. I don't remember the stuff's name but it's been gone for years.

I read that the day before a friend of mine tried an oil sump full of ATF to cure a noisy Subaru engine. It didn't work a lick.

 

[cjcride]

Originally Posted By: dailydriver
IF ATFs have very little cleaner/detergent packs in them, then WHY do the 'old school' mechanics suggest dumping a quart into the sump of a push rod engine with stuck/noisy/even collapsed hydraulic lifters??

Is there something else in ATF which could possibly help the above scenario, prompting their suggestion?

It would thin 30 weight oils from back in the day.
Now we have 5w and 0W much thinner oils.
I read this at BITOG I believe and it makes sense.

 

[philipp10]

Originally Posted By: turtlevette
Originally Posted By: bdcardinal
Originally Posted By: turtlevette
I don't understand why atf isn't loaded with cleaners. All the plungers, calibrated orifices, and other sliding parts will cause a transmission to fail if they get just slightly gummed up or filled with suspended particles.

This is a device that must stay clean to function properly.

An engine can perform fine even if all gummed up. You don't like the look but I'm not sure the engine cares until it affects flowability.



A transmission does not have thousands of controlled explosions happening every minute. They don't have to deal with blow-by, coolant intrusion, or dissimilar metal expansion rates.


That's really poor. I thought you were somewhat of a gearhead and had some understanding. I'm very disappointed.

You have steel plungers in aluminum bores with very exacting and tight clearances. A little bit of interference due to dirt or gum will cause the plunger to hang up making the unit worthless.

I could dump a cup of coolant or water in engine oil and not notice any difference in performance. My trans am at any given time has several ounces of antifreeze in the oil. I Just keep on trucking.










But what is found in a transmission are "particles" and there is no clearer that magically will remove them. Flushing the trans will help flush them out but no cleaner will dissolve them.

 

[901Memphis]

Large contaminants should be trapped by the filter. Fine contaminants will be suspended in the fluid and a line off exchange will drain most of this out. What are we arguing out exactly?

 

[demarpaint]

I'd do a pan drop, clean the screen, pan, and magnet if equipped. I'd want everything nice and clean and would like to know what's going on inside the transmission.

 

[ledslinger]

As noted, ATF has little detergency because it doesn't need much. If you think about what possibly could be cleaned if ATF was high detergency its basically two things: gummy deposits on valve body parts, and wear materials lying in the pan. Gummy deposits on valve body parts are best prevented rather than cleaned by using a fluid and service regimen to minimize deposits. Wear particles in the pan and in the filter are best left where they are because if you used a detergent fluid that dissolved them, how would they be removed from the system?

What you want is a fluid that results in minimal wear and deposits. Refreshed synthetic fluids likely do this better than mineral fluids.

Mechanics who used ATF for an engine flush were just misinformed and maybe lured by the red color. Somebody looked at the insides of many auto transmissions and never saw one with sludge except in the pan, and wrongly concluded ATF has high detergency and would be good for a flush. One of the guys who taught me the most about engines and engine machining did an ATF flush on his big block Chevy. Fortunately even though I had examples of using additives and doing things like flushes, I almost completely stayed away from them in nearly 50 years of repairing and maintaining engines.

 

[gamefoo21]

I ran an ATF flush on a car a few years back. I was running Amsoil 5w30 in it. That ATF came out black, thick, and smelled horrible.

I believe it was MaxLife Dex/Merc that I used. After that the oil stopped turning black. It had two changes at that point and I had used the Amsoil flush both times.

I ran the engine in place never drove, spun it up to around 3000 RPM a few times for 30 or so second each time, before letting it drop back to idle, during the 20 minutes I ran it.

First time I had ever heard an oil filter go into bypass, press the gas, thunk,I was sketched out because it was a new filter I used for the flush, and those Tough guard Frams aren't the most efficient filters.

So it does work in certain situations.

 

[ledslinger]

Except that ATF hasn't the level of anti wear additives of motor oil. You may have removed some contaminants (possibly no more than a motor oil flush) while likely causing some wear to high pressure wear areas.

 

[DoubleWasp]

Originally Posted By: ledslinger
. Wear particles in the pan and in the filter are best left where they are because if you used a detergent fluid that dissolved them, how would they be removed from the system?


That's why I firmly believe in effective filtering for any hydraulic system.

Most of the hydraulic systems I deal with don't have friction surfaces dissolving in them, and have 10 micron replaceable filters.

Most transmissions have friction material, and get a rock catcher media or screen door filter.

That's why I applaud certain transmissions for having a secondary spin-on filter. Nothing beats the Ford transmissions that came from the factory with sub-micron bypass filters. Those things worked so well that they would turn pitch black in 10,000 miles with new fluid still cherry red and clear as day.

That's why Ford got rid of them. Too many people thought their trans broken from the filters coming out pitch black.

 

[Pontual]

Some say that ATF is low on detergency, but high on dispersants.
When doing a dirty engine job, try to clean the finger tips with ATF ... They get instantly clean, the same or even better as when cleaned with kerosene.