# Transmission Oil Cooler



## bsb2001ca (Jan 16, 2016)

I saw a picture somewhere around here where there is an aluminum external trans cooler that then plumbs into the standard cooler/heater in the radiator. What are the temps like? Would it be beneficial to bypass the radiator cooler/warmer and just leave it at the external one so when engine temps get too warm, it's not cooking the trans oil.


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## bsb2001ca (Jan 16, 2016)

I'm asking because based on this company that sells coolers locally to me has this up, and a few other websites and transmission shops have this same info that this site does, just in other ways, and says that if we run at lower temps, we can get heaps of life from transmissions.
http://www.haydenauto.com/Featured Products-Transmission and Engine Oil Coolers/Content.aspx


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## CapitalTruck (Jun 12, 2012)

I'm sure it would help, but honestly, I just change the tranny fluid every 30-40k in my sister's Cruze tranny. It's easy enough to do.


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## Snappa (Mar 31, 2013)

How do you go about changing it? People on here have said it's easier said than done.


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## bsb2001ca (Jan 16, 2016)

Speaking of transmission cooler, I don't have the auxiliary oil to air cooler that it seems most of the cars do. More so, my cooler that runs through the rad is on the opposite side of the car than what most pictures say it is. I
Have 2 l flex lines that run on top of the back side of the rad, that then go into the rad cooler, and then return back to the transmission.. I just bought a B&M tranny cooler, so out with the rad one tomorrow and IN with the new. Going for a drive this Wednesday so I'll report back what I get with the cooler and some pics of before and after.


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## Merc6 (Jun 8, 2013)

I'll try and find a diagram again, auto cruze had a cooler but it's not easily spotted. Now on the 2nd gen I spotted something in front but it looks too huge to be a tranny cooler but oddly shaped to be a FMIC.


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## bsb2001ca (Jan 16, 2016)

Merc6 said:


> I'll try and find a diagram again, auto cruze had a cooler but it's not easily spotted. Now on the 2nd gen I spotted something in front but it looks too huge to be a tranny cooler but oddly shaped to be a FMIC.


I will take some pics. I can assure you there's no auxiliary air cooler. I can follow all the lines, and they go from trans, over the rad in flex lines to the rad, and back to the trans from the rad.


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## Merc6 (Jun 8, 2013)

Here is the best I got....

http://www.gmpartsdirect.com/auto-p...gine/cooling-system-cat/trans-oil-cooler-scat


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## bsb2001ca (Jan 16, 2016)

Merc6 said:


> Here is the best I got....
> 
> http://www.gmpartsdirect.com/auto-p...gine/cooling-system-cat/trans-oil-cooler-scat


Yah, I know. I've seen that, but the larger pic








It shows the lines run from hot side, through rad, into the air cooler, and back to the car, with most of that being on the driver side of the car, but I have my lines on the passenger side, and 2 flex lines that go straight to the rad and back to the trans.


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## Merc6 (Jun 8, 2013)

Is #2 illustrated apart of the whole radiator then?


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## spacedout (Dec 7, 2010)

bsb2001ca said:


> Would it be beneficial to bypass the radiator cooler/warmer and just leave it at the external one so when engine temps get too warm, it's not cooking the trans oil.


The proper way to hook up a trans cooler like your talking about is to leave it running through the radiator and on the output hook up the cooler. That way cold starts the transmission fluid will actually get up to operating tempetures quicker. Ever look at the Transmission temperatures on this car? Takes almost an hour driving to get fully warmed up.


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## bsb2001ca (Jan 16, 2016)

Merc6 said:


> Is #2 illustrated apart of the whole radiator then?


No. Number 2 sits outside of the rad, in front of the rad, behind the C/A and AC lines.


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## bsb2001ca (Jan 16, 2016)

spacedout said:


> The proper way to hook up a trans cooler like your talking about is to leave it running through the radiator and on the output hook up the cooler. That way cold starts the transmission fluid will actually get up to operating tempetures quicker. Ever look at the Transmission temperatures on this car? Takes almost an hour driving to get fully warmed up.


I've got a bit of driving to do tomorrow. I'll look at the temps then. My cooler has a cold temp bypass built into it. So it wouldn't go through all the fins while cold.


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## Merc6 (Jun 8, 2013)

spacedout said:


> The proper way to hook up a trans cooler like your talking about is to leave it running through the radiator and on the output hook up the cooler. That way cold starts the transmission fluid will actually get up to operating temperatures quicker. Ever look at the Transmission temperatures on this car? Takes almost an hour driving to get fully warmed up.



This. Winter was horrible on my other car even if you did the block with cardboard mod when it skipped the radiator instead of using it as a preheat element.


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## bsb2001ca (Jan 16, 2016)

Merc6 said:


> This. Winter was horrible on my other car even if you did the block with cardboard mod when it skipped the radiator instead of using it as a preheat element.


Well I'm on the west coast, near Blaine, WA and we had a mild winter. Maybe 7 degrees Celsius and 2 days of snow I think.


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## Merc6 (Jun 8, 2013)

bsb2001ca said:


> Well I'm on the west coast, near Blaine, WA and we had a mild winter. Maybe 7 degrees Celsius and 2 days of snow I think.


Here, we had snow sunday morning.


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## carbon02 (Feb 25, 2011)

bsb2001-

What engine do you have? I believe only the 1.4L with the Automatic have the tranny cooler as pictured above. I know my 2012 1.4L AT is plumbed exactly like that picture.

It's possible with the addition of the intercooler to the turbo that engineering thought the radiator cooler wouldn't be enough. 

The 1.4L AT actually has a temperature control valve which blocks off the aux cooler, until the transmission fluid gets to temperature. It appears they want to get the oil to 160-180F before additional cooling opens up. You can see this when watching the Torque App for Transmission fluid temp


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## carbon02 (Feb 25, 2011)

bsb2001-

What engine do you have? I believe only the 1.4L with the Automatic have the tranny cooler as pictured above. I know my 2012 1.4L AT is plumbed exactly like that picture.

It's possible with the addition of the intercooler to the turbo that engineering thought the radiator cooler wouldn't be enough. 

The 1.4L AT actually has a temperature control valve which blocks off the aux cooler, until the transmission fluid gets to temperature. It appears they want to get the oil to 160-180F before additional cooling opens up. You can see this when watching the Torque App for Transmission fluid temp


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## bsb2001ca (Jan 16, 2016)

I forgot that I had posted in the general powerterrain. That thermostat is #14 pictured in the pic I had uploaded. I have a 2015 1.4T 
Again.... None of that fancy cooler stuff exists in my car. There are 4 lines. 2 short ones that go from trans to just in front of the rad, which then connect to the longer lines that feed up and over the rad to the rad trans cooler.
I'll put up a vid later today.


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## pandrad61 (Jul 8, 2015)

Bypassing the trans "cooler" is a good idea if your in hot never cold climates like Florida. the temps will only be able to cool to rads temps and then lower with the oil to air cooler. like others said if your in cold climates then leave it since it keeps temps consistent. if you live in hot like me once warranty is up ill bypass the radiator heater... i mean cooler lol and go straight oil to air.


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## carbon02 (Feb 25, 2011)

The path for the fluid is first through the radiator, then the air aftercooler. So potentially lower than coolant temperatures are possible. From the air after cooler the fluid is returned to the back lower side of the transmission. Near the passenger wheel well. 

In sure I guess one could argue that bypassing the radiator may minimize heat from coolant, but you would need custom tranny lines to do so. Not a clean cut it in approach like adding an after cooler to a standard non turbo old GM or truck.


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## pandrad61 (Jul 8, 2015)

what i mean was that after it leaves the trans it cannot get any cooler untill the air to oil cooler since the radiator will not allow it to cool any more then rad temps allow.. the lines is not hard to do just get the right size fitting and use trans line. mounting it is another story


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## bsb2001ca (Jan 16, 2016)

I'm tackling mounting today. Pics to come.


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## bsb2001ca (Jan 16, 2016)

First of all, this is B&M #70268. I tried to go right into the bumper rail, minus the mounting plates it came with. Couldn't get into the aluminum. Way too hard with way too little room, so made these into a 90, and bolted all 4 to the bottom. The cooler plate already had 4 holes in the bottom plate.








Used 2 90 degree elbows to tackle the shortest line, it would just make for a kinky time with out them. Then another 90 to help keep the kinks out of the line coming out of the bottom of the rad so it's as flowy as possible.







tied it all together to keep it from rubbing.








There she is, front Center.


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## pandrad61 (Jul 8, 2015)

Very nice job. that cooler as well as bypassing the radiator will defiantly keep trans temps down, and as a added benefit there is 0% risk coolant will get into your trans lines from a failed radiator cooler. as soon as my power train is over i will do this to mine.


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## Skyviper (Apr 26, 2017)

bsb2001ca said:


> First of all, this is B&M #70268. I tried to go right into the bumper rail, minus the mounting plates it came with. Couldn't get into the aluminum. Way too hard with way too little room, so made these into a 90, and bolted all 4 to the bottom. The cooler plate already had 4 holes in the bottom plate.
> 
> 
> 
> ...


What are your transmission temps now?


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## bsb2001ca (Jan 16, 2016)

150-170 tops. It has that internal bypass below 170, so once it hits 170, thermostat opens and it’s full flow. In traffic, it will spike to 185, but within 1-2 mins it’s down to at least 170.


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