# Automatic Transmission Fluid Change Gone Bad?



## racerock (Aug 2, 2006)

Pinecone said:


> No you have to get complete mixing. If you don't completely mix the pan with the converter, you will just drain the fresh fluid in the pan each time.
> 
> The numbers I gave are based on 100% mixing of the old and new fluid.


If you do it your way, it is impossible to get 100% of the fluid out, due to the mixing of the fluids. You may reach a reasonably high percentage, but never 100%.

My preference still remains to open up the return line from the cooler and dump all the fluid into a tub that I have until it runs clean. I typically fill while running to maintain a reasonable level in the pan so it does not run overfilled, or underfilled. Every once in a while, I stop it to check (but that is on a trans with a dipstick (what a thought)).

There are many options, and opinions.


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## Pinecone (Apr 3, 2002)

Your way will still not get all the old fluid out either. And depending on how the plumbing runs, it may remove less old fluid per quart of new flid than my way. And you have no real way of knowing.

The ONLY way to get it all out (and even then it doesn't get 100%) is to remove the TC and drain it. ANY other way will have some amount of old fluid still mixed in.


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## racerock (Aug 2, 2006)

Pinecone said:


> Your way will still not get all the old fluid out either. And depending on how the plumbing runs, it may remove less old fluid per quart of new flid than my way. And you have no real way of knowing.
> 
> The ONLY way to get it all out (and even then it doesn't get 100%) is to remove the TC and drain it. ANY other way will have some amount of old fluid still mixed in.


Ah yes, yet another one of american builders better ideas (seriously). My Expedition has a drain plug in the torque converter to drain it.

Ford +2:

-A real dipstick
-A drain plug

BMW -3:

-No dipstick
-No drain plug
-Fear/risk of changing mfrs fluids...:dunno:

There are a few other things that BMW has done that just don't make sense to me. Don't get me wrong, I point out good and bad things of any vehicle I've owned and or worked on, and there have been many over the years.


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## Pinecone (Apr 3, 2002)

Yeah, there are a few out there with drain plugs ont h cenverters. A EVRY good idea, IMO.

OUr Jeep Grand Cherokee has no drain plug in the pan, you are suppsed to drop the pan to change the fluid. I use a MityVac.  I will pull thepan to change the filter shortly. It is coming up on 50K miles. But for just swapping out some fluid, the MityVac works well. Of course, without a dipstick, that doesn't work.


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## webslave1970 (Jan 23, 2008)

*M3 Atf*

I just bought a 1998 M3 auto transmision with 102K miles.
I'm thinking about changing the ATF but not sure if I should just leave it alone since it shifts fine. I could use some advice on this one. Thanks.



hoppa79 said:


> I went to a independent service center to get my transmission fluid changed ('02 330ci Step). It wasn't a complete flush, they just drained whatever came out and refilled about 4 liters.
> 
> They filled it up with Texaco ETL 7045 when they should have filled with Esso ATF LT 71141.
> 
> Does anyone know what kind of damage this might cause to my transmission. I'm kind of steamed but not sure what my options are. The last thing I wanted was to mix fluids


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