# 6T40 valve body cleaning



## XtremeRevolution (Jan 19, 2012)

How did you conclude that it was a dirty valve body that is causing your shifting issues?


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## jblackburn (Apr 14, 2012)

Have you completely exchanged/flushed the fluid? Usually that's all that's needed unless there are internal issues (slipping clutches, bad solenoids, etc).


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## Khaled Elghamari (Dec 7, 2016)

XtremeRevolution said:


> How did you conclude that it was a dirty valve body that is causing your shifting issues?


There was oil/water mixture in the trans. Please see the two pictures in my reply below


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## Khaled Elghamari (Dec 7, 2016)

jblackburn said:


> Have you completely exchanged/flushed the fluid? Usually that's all that's needed unless there are internal issues (slipping clutches, bad solenoids, etc).


Exchanged the fluid and the filter after repairing the damage.


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## Khaled Elghamari (Dec 7, 2016)

Well, it is a bit long story. There was a water/oil mixture in the trans which later got damaged and then fixed afterwards. The next day after I drove my car out of the auto shop, the shifting issue started and I was told that the TCM (solenoid pack) needs to be replaced! I replaced it but still the shifting thing occurs! So I was wondering maybe it is the valve body that was not cleaned.
Anyway, it is a long story so I just shortened it.

Any advice? I want to try and clean it my self. The is what I found in the TCM! (the picture)
View attachment 223458
View attachment 223466


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## XtremeRevolution (Jan 19, 2012)

That's going to require a complete overhaul. Find yourself a good degreaser, a transmission repair manual, and get started.


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## Khaled Elghamari (Dec 7, 2016)

XtremeRevolution said:


> That's going to require a complete overhaul. Find yourself a good degreaser, a transmission repair manual, and get started.


The transmission is already overhauled. But I don't know what happened to the TCM after that, and why I had to replace it. Note that the one installed now is of a Chevy Cruz not a Daewoo Lacetti Premier 2009. It only shifts from 2nd to 3rd and stays on 3rd (no reverse). So what is to overhaul you mean here? The valve body? I thought it may require just cleaning.


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## jblackburn (Apr 14, 2012)

Fresh fluid/a flush is the only real cleaning you can do without disassembling the entire trans again. Should be all that's needed if the box in itself is still good/was rebuilt correctly. 

I think the TCM you put in might be incompatible with your car. What trans codes are stored?


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## Khaled Elghamari (Dec 7, 2016)

jblackburn said:


> Fresh fluid/a flush is the only real cleaning you can do without disassembling the entire trans again. Should be all that's needed if the box in itself is still good/was rebuilt correctly.
> 
> I think the TCM you put in might be incompatible with your car. What trans codes are stored?


The error code was P0752... sorry for not replying earlier, internet connection was down! I want to know if there's a way to see if the problem was electrical.
I read about this error code and it's about the shift solenoid and the problem could be mechanical not electrical.


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## jblackburn (Apr 14, 2012)

Khaled Elghamari said:


> The error code was P0752... sorry for not replying earlier, internet connection was down! I want to know if there's a way to see if the problem was electrical.
> I read about this error code and it's about the shift solenoid and the problem could be mechanical not electrical.


Sounds like the solenoid itself is bad and isn't cycling.


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## Robby (Mar 1, 2013)

In the photo(s) I only see trans fluid and the white potting sealant over the circuit board.

You indicate the trans was reconditioned......what was done with the torque converter? I'm assuming it was exchanged since they cannot be effectively cleaned unless cut open, reconditioned and rewelded.

I would be inclined to replace the valve body assembly (since the electronics are part of it).

Was this entire car in deep water? 

Rob


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## dexterlab (Jun 2, 2017)

I had same problem and i changed TCU. What i have found out. ANY TCU is compatible if you make CLoning. 6T40 or 45 or 50 from any car.

youtube. com/watch?v= YO7fIpEQPd4


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