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Discussion Starter · #1 ·
Hi Everyone,

I'm going to be changing the transmission fluid and spin-on filter in my 2015 Allison MW7 6-speed.

I notice lots of threads about fluid brands.

I thought the most straight forward approach is to use a AC Delco brand Dextron VI fluid.

In my searching I have come across two different part numbers for the fluid. One is 10-9395 which may be the most current. I have also seen 88861954. The latter one appears to be what they are calling Genuine GM Fluid.

Does anyone know if there is a difference between the two? Both are Dextron VI types.

Thanks,

Jeff
 

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I swapped out my sh1tty Dex 6 at 15k miles with the double dump and double filter change when I bought my LML.

At 65k I did a single drain and refill.

Spin on filters every 20k miles

I'm a few thousand miles away from 115k miles and will double dump it again

I'll post photos of whats in the pan, when I do

:wink2:
 

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Discussion Starter · #7 ·
Hi Guys,

I appreciate your input.

I am just curious about Dextron VI. Is it really that bad? I'm not doubting the experience that others have had; but, just trying to ask the right questions.

And for the double drain, I didn't run across anything that said if there was a special method to do that? For example, should you drain, refill with the Delvac, immediately drain, and then refill? Or, should you drive the truck after the first dump/refill to dilute whatever is remaining in the pan and torgue converter? (I'm guessing it's just a matter of a few percentage points anyway after the second fill.)

I would also think that it would probably be best to replace the spin-on filter after the second dump, although it probably doesn't make that much difference. Or, am I looking at it wrong?

I had seen the article that was linked... I think it's 135 pages, and I didn't have time to go through the whole thing today.

Thanks,

Jeff
 

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The #1 design requirement for Dex 6 was very low viscosity for a fractional improvement in fuel economy. Everything else was secondary.

The #1 design requirement of a TES-295 fluid was durability, everything else was secondary.

Which fluid do you want in your transmission.

The double dump goes like this.

1. Drain fluid.
2. Remove pan and both filters
3. Clean out pan, install new internal filter, install pan and external filter (the pan gasket is reusable) Now is a good time to replace the stock pan, with a deep one. Madjack diesel has a nice kit.
4. Replace fluid. Dont obsess with getting the fluid level spot on. Anywhere between the lines is fine.
5. Drive around the block a few times.
6. Drain the pan only and refill. Dont over fill! I have the deep pan and I keep mine right at the "ADD" mark when hot. With a deep pan, this keeps the filter well submerged in the fluid, and the fluid far away from all the spinning bits.
7. Change the spin on every 20k miles ( for me, thats every other oil change)
8. In 50k miles, drain the pan and refill
9. In 100k miles, double dump it again.
10. Congrats... your Allison will now outlive you!
 

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I had seen the article that was linked... I think it's 135 pages, and I didn't have time to go through the whole thing today.
The HOOT method, as it's called, amounts to removing the connecting line coming into your transmission after cooling at the radiator/cooler and dumping the old fluid while adding new fluid, after changing the filters. The benefit over the double drain is that you spend less money buying trans fluid and one spin on filter. End result is about the same.
 
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