I see these transmissions during the "tear down" phase on YouTube and they're always very clean inside - even though the fluid is no longer red and has turned brown.
Why don't transmissions get sludge and varnish ?
- Thread starter Merkava_4
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They're not exposed to combustion gasses like engine oil is, and transmission fluid has extremely high levels of detergent in it
gathermewool
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Originally Posted By: jsfalls
They're not exposed to combustion gasses like engine oil is, and transmission fluid has extremely high levels of detergent in it
Right on one count, wrong on the next.
They're not exposed to combustion gasses like engine oil is, and transmission fluid has extremely high levels of detergent in it
Right on one count, wrong on the next.
ATF doesn't have much detergent compared to motor oil, about 1/10th as much on a standard VOA
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2727700 Not much detergents in this VOA.
Originally Posted By: steveh
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2727700 Not much detergents in this VOA.
Here is Maxlife dex/merc
http://www.pqiamerica.com/ATFdecember2012/valvolinemaxATF.htm
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2727700 Not much detergents in this VOA.
Here is Maxlife dex/merc
http://www.pqiamerica.com/ATFdecember2012/valvolinemaxATF.htm
Originally Posted By: wmj259
Don't the transmission pans have a "an okay with thumb and indexfinger" size magnet in the bottom? I thought that gathers up all the metal wear and tear from the fluid.
Yes the magnet will catch ferrous metal wear such as iron but there's still aluminum and other non ferrous metals as well as clutch material floating around which gets abrasive over time and needs drained out. A spin on filter adapter will remove lots of this as well as a Magnefine
Don't the transmission pans have a "an okay with thumb and indexfinger" size magnet in the bottom? I thought that gathers up all the metal wear and tear from the fluid.
Yes the magnet will catch ferrous metal wear such as iron but there's still aluminum and other non ferrous metals as well as clutch material floating around which gets abrasive over time and needs drained out. A spin on filter adapter will remove lots of this as well as a Magnefine
Seals are what bring most transmissions to their knee's....All the gaskets and o-rings fail due to oxidation of the fluid. This is why changing the fluid at the first 10K then every 50K after that assuming you do not have a built in drain plug is a must. If you have a built in drain plug from the OEM I like to drain and refill every 12K.
The second cause of transmission failure is tq converter issues.
It goes with out saying that heat is the enemy of an automatic.
No magic in ATF!
To answer the original question it is because of no combustion byproducts.
The second cause of transmission failure is tq converter issues.
It goes with out saying that heat is the enemy of an automatic.
No magic in ATF!
To answer the original question it is because of no combustion byproducts.
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MolaKule
Staff member
Originally Posted By: redbone3
Old mechanics (like me) used to put a quart of type A automatic transmission fluid in with the engine oil. It would quiet down hydraulic lifters, pront.
That's because it had some naphthenic base oils in it, not because of any high level of detergency.
Old mechanics (like me) used to put a quart of type A automatic transmission fluid in with the engine oil. It would quiet down hydraulic lifters, pront.
That's because it had some naphthenic base oils in it, not because of any high level of detergency.
Originally Posted By: MolaKule
Originally Posted By: redbone3
Old mechanics (like me) used to put a quart of type A automatic transmission fluid in with the engine oil. It would quiet down hydraulic lifters, pront.
That's because it had some naphthenic base oils in it, not because of any high level of detergency.
How would napthenic quiet lifters?
Originally Posted By: redbone3
Old mechanics (like me) used to put a quart of type A automatic transmission fluid in with the engine oil. It would quiet down hydraulic lifters, pront.
That's because it had some naphthenic base oils in it, not because of any high level of detergency.
How would napthenic quiet lifters?
MolaKule
Staff member
Naphthenic oils have high solvency.
Originally Posted By: JFK
Seals are what bring most transmissions to their knee's....All the gaskets and o-rings fail due to oxidation of the fluid. This is why changing the fluid at the first 10K then every 50K after that assuming you do not have a built in drain plug is a must. If you have a built in drain plug from the OEM I like to drain and refill every 12K.
Sounds like we can just drop in some transmission seal conditioner like http://www.amazon.com/Genuine-88861314-Automatic-Transmission-Conditioner/dp/B00BK7LSVM or the Lucas ones maybe. http://lucasoil.com/products/transmissio...uid-conditioner
Seals are what bring most transmissions to their knee's....All the gaskets and o-rings fail due to oxidation of the fluid. This is why changing the fluid at the first 10K then every 50K after that assuming you do not have a built in drain plug is a must. If you have a built in drain plug from the OEM I like to drain and refill every 12K.
Sounds like we can just drop in some transmission seal conditioner like http://www.amazon.com/Genuine-88861314-Automatic-Transmission-Conditioner/dp/B00BK7LSVM or the Lucas ones maybe. http://lucasoil.com/products/transmissio...uid-conditioner
MolaKule
Staff member
Originally Posted By: Merkava_4
I see these transmissions during the "tear down" phase on YouTube and they're always very clean inside - even though the fluid is no longer red and has turned brown.
As others have indicated, ATF sees no combustion gases. Additionally, an AT is a pretty much a closed system.
Varnish and sludge can form in a poorly maintained tranny and in one in which fluid temperatures have become too high (insufficient cooling).
High temperatures cause fluid oxidation which degrade the seal conditioner and AW chemistry, leading to poor sealing.
Refreshing the fluid restores the necessary additive chemistry for longer seal life.
I see these transmissions during the "tear down" phase on YouTube and they're always very clean inside - even though the fluid is no longer red and has turned brown.
As others have indicated, ATF sees no combustion gases. Additionally, an AT is a pretty much a closed system.
Varnish and sludge can form in a poorly maintained tranny and in one in which fluid temperatures have become too high (insufficient cooling).
High temperatures cause fluid oxidation which degrade the seal conditioner and AW chemistry, leading to poor sealing.
Refreshing the fluid restores the necessary additive chemistry for longer seal life.
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And yet BMW says you never have to change the transmission fluid. Seems extreme on their part. Every 100,000 miles or 6 years sounds more reasonable to me. I do think I'll put in a little seal conditioner now though. Never done it before, but who wants leaks or weak seals?
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