is putting a quart of tranny fluid in my oil recommended by you guys to clean it out?

[tuckman]

a little 5w20 or 0w20 isnt gonna make much if any difference.

Let's say you 10w30..... at operating temperature, it acts like a 10 weight, dilute that with a quart with 5 weight after you drain out a quart.... you are gonna have what basically is just a little thicker than 9 weight, 0 weight is just gonna change it to ~9 weight. Any good thin clean fresh quality oil is gonna work, but it has nothing really to do with the weight of the oil. The thin oil just mixes more readily, and the additives are still in suspension, whereas your old oil may have additives that are no longer in suspension, or are worn out.

I do not agree with the oil weight theory, it is just wrong.
At operating temps a 10w-30 does NOT act like a 10 weight it is a 30 weight with 10w cold temp characteristics! Just like a 0w-30 will still have the same viscosity at operating temps as a 10w-30 or 5w-30 but it will still be pourable at much colder temps, easily into the -40's. Where a 10w-30 would be a glob stuck in the bottle at even at -25. That is why a 5w-20 is thinner than a 5w-30 at operating temps but will be similar viscosity at 40 and pourable at -20 and lower.
Once the oil has been in use for a long time the 30 weight starts to thicken into 40 or higher weight oil and cause sludge if not changed at proper intervals. That is where this old trick came from there was not a readily available supply of thin oils other than ATF so it was the choice. If you are using 10w-40 or 20w-50 the light oil is gonna make an even bigger difference.

I do agree with using lighter weight diesel motor oils.
I have a good stash of diesel motor oils for my vehicles and use them regularly. These oils have the strongest additive packs and very good cleaning additives as these oils have to deal with soot.

 

[Turdle]

I have used the transmission fluid flush trick on several engines over the years with no ill effects.
Every used car we buy, or, any used engine I work on gets the trans fluid in the crankcase, run to operating temp, then drained and filled with new oil. Heck I even add about 1/2 can of sea-foam also in the flush fill.

I think trans fluid has a higher level of detergents which hold the debris in suspension longer, which allows them to flow out when drained--

I have no scientific data to back it up, just great results.

 

[tuckman]

Oil analysis shows that ATF has less detergents than engine oil.

 

[FIND]

Opera House, just a tip..... Gasoline will cause oil to thicken.

I do not agree with the oil weight theory, it is just wrong.
At operating temps a 10w-30 does NOT act like a 10 weight it is a 30 weight with 10w cold temp characteristics! Just like a 0w-30 will still have the same viscosity at operating temps as a 10w-30 or 5w-30 but it will still be pourable at much colder temps, easily into the -40's. Where a 10w-30 would be a glob stuck in the bottle at even at -25. That is why a 5w-20 is thinner than a 5w-30 at operating temps but will be similar viscosity at 40 and pourable at -20 and lower.
Once the oil has been in use for a long time the 30 weight starts to thicken into 40 or higher weight oil and cause sludge if not changed at proper intervals. That is where this old trick came from there was not a readily available supply of thin oils other than ATF so it was the choice. If you are using 10w-40 or 20w-50 the light oil is gonna make an even bigger difference.

I do agree with using lighter weight diesel motor oils.
I have a good stash of diesel motor oils for my vehicles and use them regularly. These oils have the strongest additive packs and very good cleaning additives as these oils have to deal with soot.

sorry, for some reason I reversed the numbers, dont ask why, I was tired. Silly mistake, I'm sure it detracts from my credibility, but I guess that happens. I will edit my post though, just to clear things up for others who may read it. Either way, adding one quart of lighter oil does not thin the oil an appreciable amount. The benefit you are getting from adding a fresh (lighter) oil is due to the fact that the additives are still in suspension, and the fact you can guarantee there are more viscosity index improvers in the oil means more that can mix with the sludged off oil. This is where the ATF trick came about. It had nothing to do with the detergents in the oil, it had to do with the VII's and the anti-foaming agents that could when heated, mix the sludge back into oil and move the air out.

You will get nearly the same result from an oil of the same weight. Though, as you have suggested, I still like oil for diesel engines, since it does have added detergents, and the formulations are pretty good for cleaning.

 

[tuckman]

The thread I started on bob is the oil guy dot com about this very subject is now 4 pages long now! There is a poster that states that GM issued a TSB in 1970ish, to add ATF to the engine oil to THIN it out to reduce/eliminate lifter tick.
here is the thread
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1817600&nt=4&page=1

 

[FIND]

The Viscosity Index Improvers in ATF will thin oil.

BUT that is not really my point. Adding thinner oil will of course thin oil, BUT, marginally thinner oil will not clean an engine an appreciable amount more than oil of the proper viscosity.

Viscosity numbers are kind of misleading, try comparing 20 weight and 30 weight oil at 200 degrees. You are really only talking about a very slight ability to flow into an area a few thousands of an inch smaller with a little less pressure. I mean, saying 20 weight and 40 weight sounds like a huge difference, but it really isnt, especially in open areas like above rockers where the sludge accumulates.

You can clean grease off your hands using oil yes. Because oil mixes with grease, since they are basically the same thing. But you wont get an appreciable difference between washing with a 20 weight or washing with a 30 weight.

Also, adding just a quart of lower weight oil, doesnt really thin the oil much, like I have been telling you.

Part of the deal with the GM TSB in the 70s is the fact that most people who experienced the problem were using 10w40 or single weight oil.

Let me put this another way for you.... Fresh oil as a cleaner is the same principle you would apply when you look at the complaints of people saying synthetic "caused" their engine to leak. Fresh stable oil with a fresh stable additive package = cleans up deposits. Synthetic oil is not any thinner than Dino oil, but it still cleans "better", this is why. That and the fact that it stays stable longer and holds additives in suspension longer.

 

[tuckman]

So we both agree that ATF is not really an engine cleaner? That the act of adding a fresh quart of engine oil would have the same effect as adding a quart of ATF, to a neglected/sludgy motor? Also that there are much more effective engine cleaners on the market?

On a side note
The first synthetics had little or no seal swell additives. So the combination of cleaning out the deposits on the seals it would shrink old seals, thus causing leaks in older motors that previously run dino. Today's synthetics all have additive packs that keep this from happening as it did in the past, a person can switch from syn to dino without worry.

 

[FIND]

So we both agree that ATF is not really an engine cleaner? That the act of adding a fresh quart of engine oil would have the same effect as adding a quart of ATF, to a neglected/sludgy motor? Also that there are much more effective engine cleaners on the market?

Fresh quart of engine oil would have the same (probably better) effect as adding a quart of ATF, and yeah, there are MUCH better cleaners. I have run a pint or two of diesel fuel into an engine once or twice in the past even before a rebuild when I knew the engine looked horrible on the inside.

On a side note
The first synthetics had little or no seal swell additives. So the combination of cleaning out the deposits on the seals it would shrink old seals, thus causing leaks in older motors that previously run dino. Today's synthetics all have additive packs that keep this from happening as it did in the past, a person can switch from syn to dino without worry.

didn't really want to get into all the issues, just saying, the good stuff in the synthetics would clean off the gunk, and then stuff would leak out because there was no gunk to clog it. Dino oil can have the same effect when changed on short interval and using a quality dino.

 

[tuckman]

Vermillion, SD...I live near Vermillion, Alberta, Canada.

 

[FIND]

WIN

We are like neighbors

Only one state and a province between us.

strangely, I have talked to one other guy before on some forum who was from Vermillion, Alberta Canada.

 

[tuckman]

I have gotten a more definitive answer on the use of ATF in oil, this again is from a guy who is extremely knowledgeable in lubrication as he is a professional in the field.
Quote
"We need to qualify the time line and chemistries involved in this topic.

Back in the days ('50-'70) when people were running 10W40 and at a minimum, 10W30, the detergency package of those oils were less than that found in ATF.

Putting in a quart of 5W20 ATF before the oil change, not only thinned the oil, but provided a small increase in oil detergency and increased the dispersancy somewhat, because the ATF used naphthenic base oils.

Today, ATF has less detergents and less dispersants than modern engine oils, and offers no real AW protection over that of engine oils.


Of course, adding ATF to an engine which has a 5W20 or 0W20 engine oil is not going to do much with the vicosity, but again, offers no advantage wrt cleaning properties.

In my '62 Chevy with a 283, I too had a modulator diaphram leak in the PowerGlide which fed ATF from the tranny to the intake manifold. The burning of ATF deposited black soot on the plugs and blackended the tailpipe. The pistons affected had a layer of thick sooty deposits on them. If I had a tailgator, I would just back-off on the accelerator, which increased vacuum, and blew out some beautiful smoke which either made him pass or back-off."

This helps show that ATF in the past did have its place, but does not do what it used to.