ATF change in GM 10 Speed

[MurkyAsparagus]

No such thing as Dexron 6. It's VI, as in V.I.
Same that Dexron LV isn't Dexron 55.

You’re right, but I think in practice it doesn’t matter.

I’m not walking into a parts store and telling them I want Dexron V - I, I want Dexron 6.

In contrast, if I walk in, I’m not telling them I want Dexron Low or Ultra Low Viscosity, I want Dexron LV or ULV.

It’s a matter of numerical version vs fluid type (Dexron III and VI / Dexron LV and ULV)

 

[Sumboodie]

You’re right, but I think in practice it doesn’t matter.

I’m not walking into a parts store and telling them I want Dexron V - I, I want Dexron 6.

In contrast, if I walk in, I’m not telling them I want Dexron Low or Ultra Low Viscosity, I want Dexron LV or ULV.

It’s a matter of numerical version vs fluid type (Dexron III and VI / Dexron LV and ULV)

If you ask me for Dexron 6... or worst yet "dextron" 6, I'll correct you. We don't sell much of it, mostly Delo Syn ATF, MD3, P66 VersaTrans LV, Delo 668, few others.

I'd expect if any place, here would be less willing to accept incorrect names for oil.

Maybe I'll go get some Mobile ansdCasterOil too. And some Murcron

 

[martinq]

No such thing as Dexron 6. It's VI, as in V.I.
Same that Dexron LV isn't Dexron 55.

There was Dexron, II, III, and VI in the past and we tend to refer them as 1,2,3 and 6 for ease of communication.

https://en.wikipedia.org/wiki/DEXRON

 

[Sumboodie]

There was Dexron, II, III, and VI in the past and we tend to refer them as 1,2,3 and 6 for ease of communication.

https://en.wikipedia.org/wiki/DEXRON

Correct. After III (version 3) though it's VI.

Just took a course on ATF. Mostly Ford, GM and Chrysler.

 

[MurkyAsparagus]

There was Dexron, II, III, and VI in the past and we tend to refer them as 1,2,3 and 6 for ease of communication.

https://en.wikipedia.org/wiki/DEXRON

This is exactly what I was trying to say, thanks martinq!

 

[martinq]

IMO, with transmissions, I don’t think the whole thick vs thin fuel economy debate really comes into play. They are incredibly more complex and everything has to work just right. The solenoids, valve bodies, and everything else has to be absolutely perfect. We are fitting 10 speeds in a smaller form factor than 6 speeds years ago. Thinner fluids might just have to be present in order to properly lubricate, flow through smaller channels with the overall smaller and more compact size, and everything else.

All my opinion, however.

The viscosity argument makes very little sense when you put it that way. There is nothing in these transmissions that is "absolutely perfect" and they are very tolerant (or should be programmed to) conditions beyond "just right".

How does the viscosity of an ULV fluid at 40C compare to a Dex6 at 100C?

What is the typical viscosity of ULV fluid at -40C, 0C, 40C, 100C and 150C... and of those, which one is perfect?

 

[Nuclear_42]

***I did this and then had to undo it.***

I had the 10r80 and mine was giving me trouble. Of course I tried a fluid change and of course as an amsoil fan I tried the D/F to amsoil. I mean, their website says I could!

First, it didn’t fix the problem, but we will leave that there.

The thicker fluid was notable. At first it just felt like firmer shifts. But really what I think was going on was the thicker fluid delayed completion of the shift, and when they finally locked into the next gear it kinda “slapped” into engagement. It was worse. It was not better.

Lesson learned. Redid with Valvoline ULV with a partial dose of lubegaurd red for the win.

Now - the ford version of the 10r80 showed some bushing galling on the CDE drum (observed in videos). So I ended up with, after those 2 D/F, still a little amsoil in the mix. So, subsequent D/F I stayed with 3/4 ULV and 1/4 amsoil, with 1/4 bottle lubeguard red. That kept a *slightly* thicker fluid and presumably additive pack in there, but on,y slightly.

I traded my f150 recently and it broke down while the dealer test drove it (hard, the evidence suggests). The transmission, with that mix, was not what failed on them. BUT, it was primarily ULV with only a little LV fluid in the mix. A pure LV fluid swap won’t be great. Maybe it will work if you can recalibrate it on the GM (fords implementation has adaptives which one can reset with forscan software).

Back to ULV, it simply shifts quicker and with less drama in that trans.

@Kestor

Amsoil now offers Signature ULV.

 

[nthach]

IMO, with transmissions, I don’t think the whole thick vs thin fuel economy debate really comes into play. They are incredibly more complex and everything has to work just right. The solenoids, valve bodies, and everything else has to be absolutely perfect. We are fitting 10 speeds in a smaller form factor than 6 speeds years ago. Thinner fluids might just have to be present in order to properly lubricate, flow through smaller channels with the overall smaller and more compact size, and everything else.

All my opinion, however.

And the TCM is also monitoring shift times via watching the solenoid PWM values and shaft speeds to see if shifts are done within an expected time. If not, CEL and trans codes are logged. GM figured out how to monitor clutch life based on servo fill times. They were monitoring shift solenoid on/off times and pressure transducers to deduce that data.

Toyota recently introduced a new ATF for their fifth gen hybrid system, e-Transaxle Fluid TE. It’s a ULV fluid, and while their hybrid drive units don’t have valve bodies or operate like a CVT/stepped AT, the hybrid ECU is always looking at sensor values to make sure all is well. It’s a ~4cst fluid, compared to ~5-6cst for ATF WS/MaxLife.

 

[meep]

Amsoil now offers Signature ULV.

Good to know! If I still had a 10R80, I’d be all over it at next maint interval.

 

[ctechbob]

The amount of gear changing gymnastics that these 10 speeds have to pull off is immense, and all of it relies on very specific shift timing. You might think that ULV is too thin, but the whole transmission was designed around it, specifically the valve body. Lots of people notice odd behavior on cold fluid and that is why. You want these transmissions up to operating temp as quick as possible and the fluid to be right where it is supposed to be which is right around 4.5 cSt @100deg.

Some people get lucky and can go thicker, but most don't luck out.

So far there seem to be 5 fluids that are readily available out in the wild. Dexron ULV, Mercon ULV, Valvoline ULV, and the offerings from Amsoil and HPL (I forget their exact nomenclature)

There are several other brands that have a ULV fluid but they're not widely available at the retail level for us DIY'ers.

While I use Maxlife in my Honda Cars, 10R's and 10L's are one place it should never be.