On the weekend I did a very unscientific comparison of the anti-foam characteristics of some ATFs. Here's what I did:
1. Heat the ATF to 130°F/54°C (touchable yet warm).
2. Beat for 2 min with a Dremel wire brush.
3. Observe bubbles at 0 sec, 10 sec, and 60 sec.
The observations:
Valvoline Maxlife VV324 Dex/Merc
Very little bubble formation during beating, those that form coalesce quickly, all gone by 60 sec.
Coastal (Warren Unilube) ATF+4
Slight bubble formation during beating, coalesce quickly, all gone by 60 sec.
Mobil 1 (silver bottle purchased this spring)
Some bubble formation; most bubbles coalesce quickly and pop; a few persist at 60 sec.
Supertech (Warren Performance) Dexron VI
Moderate frothing during the beating; the small bubbles fizz to the surface within 10 sec. Many coalesce and remain at 60 sec.
B&M TrickShift (old half-full bottle of unknown age, obtained from neighbor)
Fluid is dyed blue! Considerable frothing during the beating; fizz at the surface for 10 sec. The bubble coalesce and remain for several minutes. Interesting observation: fluid cast-off during the beating was much less than other fluids.
I took pictures, but they're not terribly illustrative, and this is a really crude test. I'd love to see how different ATFs perform in a proper foam test like ASTM D892 or D6082.
I was motivated to do this experiment after seeing some bubbles on my trans dipstick after some mountain driving that was followed by gear grinding on the short drive home. It's a 2005 4T65-E-HD transmission that I had nearly 100% full of Supertech Dexron VI that was only 7100 mi old. Seeing that the Maxlife performed the best in my test and is supposedly a valid Dexron-IIIH replacement, I changed 5.5 qt of it into the car. The trans does shift somewhat firmer now, so it must have some different frictional properties.
1. Heat the ATF to 130°F/54°C (touchable yet warm).
2. Beat for 2 min with a Dremel wire brush.
3. Observe bubbles at 0 sec, 10 sec, and 60 sec.
The observations:
Valvoline Maxlife VV324 Dex/Merc
Very little bubble formation during beating, those that form coalesce quickly, all gone by 60 sec.
Coastal (Warren Unilube) ATF+4
Slight bubble formation during beating, coalesce quickly, all gone by 60 sec.
Mobil 1 (silver bottle purchased this spring)
Some bubble formation; most bubbles coalesce quickly and pop; a few persist at 60 sec.
Supertech (Warren Performance) Dexron VI
Moderate frothing during the beating; the small bubbles fizz to the surface within 10 sec. Many coalesce and remain at 60 sec.
B&M TrickShift (old half-full bottle of unknown age, obtained from neighbor)
Fluid is dyed blue! Considerable frothing during the beating; fizz at the surface for 10 sec. The bubble coalesce and remain for several minutes. Interesting observation: fluid cast-off during the beating was much less than other fluids.
I took pictures, but they're not terribly illustrative, and this is a really crude test. I'd love to see how different ATFs perform in a proper foam test like ASTM D892 or D6082.
I was motivated to do this experiment after seeing some bubbles on my trans dipstick after some mountain driving that was followed by gear grinding on the short drive home. It's a 2005 4T65-E-HD transmission that I had nearly 100% full of Supertech Dexron VI that was only 7100 mi old. Seeing that the Maxlife performed the best in my test and is supposedly a valid Dexron-IIIH replacement, I changed 5.5 qt of it into the car. The trans does shift somewhat firmer now, so it must have some different frictional properties.
