FYI Some good Transmission tips

[JCL]

Originally Posted by Ghost-Flame

I clearly don't understand. If particulates are held in suspension how can sludge build up? If particulates are held in suspension then why am I not flushing them out when I drain and fill? If particulates are held in suspension then abrasives are constantly wearing on your mating surfaces with never a break, how can that be better than new fluid?

100,000 miles is the life of the transmission after it has been prematurely chewed up by dirty, micro gritty atf,that is left in by the Motor Werks. They like... no love... to take your 6,000 clams when THEIR dirty atf has ruiend the transmission before its time. when atf changes could have prolonged trans failure and the extraction of said $6000.

If the above old fluid theory was true then ... I don't know do I?

PS I have the next 33 bottles of atf ageing on a shelf in my garage... I rotate it and turn it every month... Orson Wells checks in occasionly to see what's up.

The particulates that are held in suspension are not significantly abrasive. They are predominantly friction plate material. If they were abrasive, then your shifts would not be very smooth. They provide colour to the fluid, but do not change the fluid friction properties. They do change the viscosity, and the transmission adjusts for that within a predetermined range.

The sludge in the bottom of the pan is the stuff that didn't go through the strainer at the oil pickup (prior to the filter). It just sits in the pan, and doesn't hurt anything. It is on the dirty side of the filter, not the clean side. It does start to hurt things when it accumulates to the point where it blocks the filter.

The screen and filter are designed to separate out the particles that are large enough to do damage. That is why you want to use an OE filter, so that you don't buy a filter that has a larger micron rating that lets larger particles through. The ones that pass through the OE filter are of a size that they aren't considered critical. There aren't gritty metal particles circulating through the filter and abrading bearing surfaces. That is an exageration.

All that said, nothing is absolute, and that is why particles in suspension can get trapped in small passageways. There is not a significant flow through those passageways, they are more like dead ends. Over a long period of time, particles can collect there. Such is life.

I think you are considering the transmission fluid as primarily a lubricant. While it has that function, it is not a demanding lubrication requirement IMO, and the transmission fluid has many other functions. It is predominantly a heat exchanging medium, and it needs to be non-compressible as it is a hydraulic fluid. The lubrication function is so low on the requirements list that Dexron ATF, a 10 weight straight-grade mineral oil with few lubricating additives, can function for 200,000 miles while not breaking down. This isn't an engine, with high lubricating demands.

Hope some of that helps. I am not trying to change your mind on whether you should change your ATF, you have already made that decision and your inventory alone suggests you will keep changing it. Let me know what you think of the training materials I posted above.