Transmission Cooler

[ABFoz]

Hi mates, I am thinking of installing a plate-and-fin or stacked-plate oil cooler for my 4EAT. I hear good reviews on the OZ-made Davies Craig. The stacked-plate ones are good, as well, but I will have to make some brackets for it instead of just being attached to the condenser. This is the first time I am considering an oil cooler because I used to have manual gearboxes for off-road use.

Can anyone share his/her insights on a good brand? Cheers.

 

[Kevin]

I have an added oil cooler but it was installed as part of a tow pack by Subaru when the car was new. Of course there is already an oil "cooler" incorporated in the bottom of the radiator for AT vehicles where the term "cooler" is a bit misleading as it also warms the ATF in colder climates to bring the transmission up to operating temperature.

In warmer climates the radiator "cooler" is often bypassed and connected directly to an added cooler which provides two benefits 1) the ATF actually gets cooled and 2) hot ATF does not increase the radiator coolant temperature and send your temp gauge through the roof; I've had that happen when beach driving in very soft sand.

In colder climates I'd most likely leave well-enough alone ;-)

So, I guess your decision is will it be of any benefit in your climate.

 

[ABFoz]

Yes, my stock trans oil cooler is at bottom of the radiator. I am thinking of diverting the operation from that to an aftermarket cooler but I am also aware of the trade-off in alpine conditions. I am not planning to tow with my 2.0 but with beach and dune driving, it might give some help?

I always monitor my temp when I am on the dunes and the only time I smelled fluid was when I was going up and down. I am not sure if I am just overthinking and the stock system is adequate enough. Cheers.

 

[Kevin]

Maybe install a valve to redirect the ATF to the radiator in winter?

 

[ABFoz]

That is a really good idea! I will look into it and do some research. Cheers.

 

[El_Freddo]

The "cooler" in the radiator for the auto is actually to keep the ATF at operating temp in cooler climates, it's also to aid getting the ATF up to operating temp quicker.

This is why you'll find larger/oversized coolers fitted on the line from the auto trans, then to the radiator's "cooler". If the external cooler isn't big enough for what you're doing, or the climate you're operating in, or both, you'll see a rise or spike in engine coolant temp. This can give a very false reading on actual engine temp - as in, "what's wrong with my engine" type issue - it's actually the ATF creating that heat in the engine's cooling system.

I hope that makes sense.

Cheers

Bennie

 

[ABFoz]

I thought of bypassing it but I am now thinking of installing one in series to be able to use the radiator's aid in getting the ATF to operating temperature.

I talked to Subaru NZ and they said that they don't recommend such as they do it by the book. We also didn't get the oil package genuine cooler here. According to them, as long as the water temp is OK, the ATF temp should be OK, as well.


I just don't like the extra smell that I get when I get up and down the dunes, even though the water temp is still OK. The smell is only when I am playing in the dunes, by the way.

My ATF oil still looked OK after my dune tours but I drain-and-fill my ATF every 30,000km, anyway, as recommended by Subaru for NZ conditions.

I am still gathering some info on such an upgrade as I want to get the best efficiency from both the cooling of an external system and the warming up of the fluid by the radiator. Cheers.

 

[Kevin]

I thought of bypassing it but I am now thinking of installing one in series to be able to use the radiator's aid in getting the ATF to operating temperature.

I talked to Subaru NZ and they said that they don't recommend such as they do it by the book.

Interesting they should say that when mine was actually installed by Subaru :iconwink:

 

[ABFoz]

Interesting they should say that when mine was actually installed by Subaru :iconwink:

It's interesting, actually. They said that the valve body and the lockup in my JDM 4EAT are aggressive so fluid drive is not that much used compared to other autos. I will still look into this though. I even found the one that OZ uses for their Subarus.

[MENTION=114]Kevin[/MENTION], is yours installed in series with the heat exchanger at the bottom of the radiator? Cheers.

 

[Kevin]

Yes, in series because I would go winter camping / offroading and to the snow with it every year but am tempted to change it now that I generally use the Triton for such trips.

 

[ABFoz]

I checked my trip journal and the smell came out only in the sticky sand area last year. No lights came out and it still drove fine.

4 body-on-frame vehicles got stuck here but the SG did a good job. I inferred 2 things about the smell now, a) I used fluid drive a lot in this section and b) the fluid is already due for a service so it wasn't at it's most effective state. When I went up and down the dunes, the car crawled with wheel spin so there is lockup in the torque converter and it was cool that time.

I am now using Motul ATF-1A and the 4EAT SportShift just performed extremely well with it. Even my last Northland trip with a lot of sand and uphills, the car behaved well.

I think I will just carry on with the current fluid cooling system it brings the transmission's temperature quicker than when an additional air-to-fluid cooler is installed. Cheers.